Nutrient chapter

Cold water immersion

Cold water immersion. Species, exposure and limitations are retained in each linked claim.

67 recorded mechanisms · 5 availability situations · 1 preserved sources. Draft and verified records are labeled separately.

Read recorded mechanisms Open recursive mind map

The mechanisms

What the sources say this nutrient does, one relationship at a time. Plain wording comes first; the technical statement follows.

Cultured sensory neurons and intact sensory nerve fibres from TRPM8-deficient mice showed profoundly diminished responses to cold, demonstrating an essential and predominant role for TRPM8 in thermosensation over a wide range of cold temperatures.
Transient receptor potential melastatin 8 / TRPM8 cold and menthol receptor → Cold-evoked firing of primary afferent sensory neurons source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/17538622.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "94d6ed0e3d36f9530a7bb47b1635ee1fd438bb60aced91efd69d544b13d18300", "start_char": 0, "end_char": 1451, "text_sha256": "94d6ed0e3d36f9530a7bb47b1635ee1fd438bb60aced91efd69d544b13d18300"}
experimental_model
TRPM8-deficient mice with cultured sensory neurons, intact nerve fibre recording and behaviour
exposure
Ambient cooling below about 26 degrees C; menthol as a chemical agonist
limitations
A genetic loss-of-function study. TRPM8 mutant mice still avoid surfaces below 10 degrees C, so the channel is the principal but not the only cold detector.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Mouse
plain_language
One ion channel is what actually reports cold to the nervous system.
primary_references
[cold-p17538622] The menthol receptor TRPM8 is the principal detector of environmental cold. (2007). https://pubmed.ncbi.nlm.nih.gov/17538622/ DOI: 10.1038/nature05910
tissue_or_cell_type
Primary afferent sensory neurons
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 65–76
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · TRPM8-deficient mice with cultured sensory neurons, intact nerve fibre recording and behaviour · source_derived_draft · unverified_draft
### cold-trpm8-cold-detector Cultured sensory neurons and intact sensory nerve fibres from TRPM8-deficient mice showed profoundly diminished responses to cold, demonstrating an essential and predominant role for TRPM8 in thermosensation over a wide range of cold temperatures. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: One ion channel is what actually reports cold to the nervous system. organism: Mouse tissue_or_cell_type: Primary afferent sensory neurons experimental_model: TRPM8-deficient mice with cultured sensory neurons, intact nerve fibre recording and behaviour limitations: A genetic loss-of-function study. TRPM8 mutant mice still avoid surfaces below 10 degrees C, so the channel is the principal but not the only cold detector. exposure: Ambient cooling below about 26 degrees C; menthol as a chemical agonist evidence_span: {"source_cache": "artifacts/cold-research/17538622.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "94d6ed0e3d36f9530a7bb47b1635ee1fd438bb60aced91efd69d544b13d18300", "start_char": 0, "end_char": 1451, "text_sha256": "94d6ed0e3d36f9530a7bb47b1635ee1fd438bb60aced91efd69d544b13d18300"} [cold-p17538622] The menthol receptor TRPM8 is the principal detector of environmental cold. (2007). https://pubmed.ncbi.nlm.nih.gov/17538622/ DOI: 10.1038/nature05910
Complete structured claim and evidence
TRPM8-deficient animals showed clear behavioural deficits in discriminating between cold and warm surfaces and in responding to evaporative cooling, while still avoiding surfaces below 10 degrees C with reduced efficiency.
Experimental TRPM8-deficient mouse genotype → Behavioural discrimination between cold and warm surfaces source_derived_draftungraded
Experimental context and source evidence
availability_state
machinery_impairment Imported condition classification; unverified.
evidence_span
{"source_cache": "artifacts/cold-research/17538622.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "94d6ed0e3d36f9530a7bb47b1635ee1fd438bb60aced91efd69d544b13d18300", "start_char": 0, "end_char": 1451, "text_sha256": "94d6ed0e3d36f9530a7bb47b1635ee1fd438bb60aced91efd69d544b13d18300"}
experimental_model
TRPM8-deficient mice with cultured sensory neurons, intact nerve fibre recording and behaviour
exposure
Ambient cooling below about 26 degrees C; menthol as a chemical agonist
limitations
A genetic loss-of-function study. TRPM8 mutant mice still avoid surfaces below 10 degrees C, so the channel is the principal but not the only cold detector.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Mouse
plain_language
Without the channel the animal cannot tell cold from warm, though extreme cold still registers somehow.
primary_references
[cold-p17538622] The menthol receptor TRPM8 is the principal detector of environmental cold. (2007). https://pubmed.ncbi.nlm.nih.gov/17538622/ DOI: 10.1038/nature05910
tissue_or_cell_type
Primary afferent sensory neurons
trigger_kind
machinery_impairment Imported condition classification; unverified.
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 78–89
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · TRPM8-deficient mice with cultured sensory neurons, intact nerve fibre recording and behaviour · source_derived_draft · unverified_draft
### cold-trpm8-null-behaviour TRPM8-deficient animals showed clear behavioural deficits in discriminating between cold and warm surfaces and in responding to evaporative cooling, while still avoiding surfaces below 10 degrees C with reduced efficiency. Condition category: machinery_impairment nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Without the channel the animal cannot tell cold from warm, though extreme cold still registers somehow. organism: Mouse tissue_or_cell_type: Primary afferent sensory neurons experimental_model: TRPM8-deficient mice with cultured sensory neurons, intact nerve fibre recording and behaviour limitations: A genetic loss-of-function study. TRPM8 mutant mice still avoid surfaces below 10 degrees C, so the channel is the principal but not the only cold detector. exposure: Ambient cooling below about 26 degrees C; menthol as a chemical agonist evidence_span: {"source_cache": "artifacts/cold-research/17538622.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "94d6ed0e3d36f9530a7bb47b1635ee1fd438bb60aced91efd69d544b13d18300", "start_char": 0, "end_char": 1451, "text_sha256": "94d6ed0e3d36f9530a7bb47b1635ee1fd438bb60aced91efd69d544b13d18300"} [cold-p17538622] The menthol receptor TRPM8 is the principal detector of environmental cold. (2007). https://pubmed.ncbi.nlm.nih.gov/17538622/ DOI: 10.1038/nature05910
Complete structured claim and evidence
M8-B decreased deep body temperature in Trpm8-positive mice and rats but not in Trpm8-null mice, and intravenous administration was more effective than intrathecal or intracerebroventricular, indicating a peripheral action.
M8-B, a selective TRPM8 antagonist → Core (rectal) body temperature source_derived_draftungraded
Experimental context and source evidence
availability_state
machinery_impairment Imported condition classification; unverified.
evidence_span
{"source_cache": "artifacts/cold-research/22323721.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "c0ead3b0097eaa75bf74d806e7f40bc61da4275cdd0af92735be9cad681ed3f0", "start_char": 0, "end_char": 1784, "text_sha256": "c0ead3b0097eaa75bf74d806e7f40bc61da4275cdd0af92735be9cad681ed3f0"}
experimental_model
Rats and mice with a selective TRPM8 antagonist given by several routes
exposure
M8-B intravenously, intrathecally or intracerebroventricularly, at constant or changing ambient temperature
limitations
On-target action is supported by the absence of effect in Trpm8-null mice. The peripheral site of action is inferred from route comparison, not from direct measurement at the nerve ending.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Rat, mouse and human channels in vitro
plain_language
Blocking the skin cold sensor makes the body cool down, because it never learns it is cold.
primary_references
[cold-p22323721] Pharmacological blockade of the cold receptor TRPM8 attenuates autonomic and behavioral cold defenses and decreases deep body temperature. (2012). https://pubmed.ncbi.nlm.nih.gov/22323721/ DOI: 10.1523/jneurosci.5606-11.2012
tissue_or_cell_type
Skin sensory neurons and thermoeffectors
trigger_kind
machinery_impairment Imported condition classification; unverified.
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 91–102
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Rats and mice with a selective TRPM8 antagonist given by several routes · source_derived_draft · unverified_draft
### cold-trpm8-blockade-temperature M8-B decreased deep body temperature in Trpm8-positive mice and rats but not in Trpm8-null mice, and intravenous administration was more effective than intrathecal or intracerebroventricular, indicating a peripheral action. Condition category: machinery_impairment nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Blocking the skin cold sensor makes the body cool down, because it never learns it is cold. organism: Rat, mouse and human channels in vitro tissue_or_cell_type: Skin sensory neurons and thermoeffectors experimental_model: Rats and mice with a selective TRPM8 antagonist given by several routes limitations: On-target action is supported by the absence of effect in Trpm8-null mice. The peripheral site of action is inferred from route comparison, not from direct measurement at the nerve ending. exposure: M8-B intravenously, intrathecally or intracerebroventricularly, at constant or changing ambient temperature evidence_span: {"source_cache": "artifacts/cold-research/22323721.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "c0ead3b0097eaa75bf74d806e7f40bc61da4275cdd0af92735be9cad681ed3f0", "start_char": 0, "end_char": 1784, "text_sha256": "c0ead3b0097eaa75bf74d806e7f40bc61da4275cdd0af92735be9cad681ed3f0"} [cold-p22323721] Pharmacological blockade of the cold receptor TRPM8 attenuates autonomic and behavioral cold defenses and decreases deep body temperature. (2012). https://pubmed.ncbi.nlm.nih.gov/22323721/ DOI: 10.1523/jneurosci.5606-11.2012
Complete structured claim and evidence
M8-B affected all thermoeffectors studied, including thermal preference, tail-skin vasoconstriction and brown fat thermogenesis, suggesting that TRPM8 is a universal cold receptor in the thermoregulation system, and it attenuated cold-induced c-Fos expression in the lateral parabrachial nucleus.
Transient receptor potential melastatin 8 / TRPM8 cold and menthol receptor → Brown adipose tissue thermogenesis source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/22323721.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "c0ead3b0097eaa75bf74d806e7f40bc61da4275cdd0af92735be9cad681ed3f0", "start_char": 0, "end_char": 1784, "text_sha256": "c0ead3b0097eaa75bf74d806e7f40bc61da4275cdd0af92735be9cad681ed3f0"}
experimental_model
Rats and mice with a selective TRPM8 antagonist given by several routes
exposure
M8-B intravenously, intrathecally or intracerebroventricularly, at constant or changing ambient temperature
limitations
On-target action is supported by the absence of effect in Trpm8-null mice. The peripheral site of action is inferred from route comparison, not from direct measurement at the nerve ending.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Rat, mouse and human channels in vitro
plain_language
The same sensor feeds every cold defence: behaviour, blood vessels and heat production.
primary_references
[cold-p22323721] Pharmacological blockade of the cold receptor TRPM8 attenuates autonomic and behavioral cold defenses and decreases deep body temperature. (2012). https://pubmed.ncbi.nlm.nih.gov/22323721/ DOI: 10.1523/jneurosci.5606-11.2012
tissue_or_cell_type
Skin sensory neurons and thermoeffectors
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 104–115
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Rats and mice with a selective TRPM8 antagonist given by several routes · source_derived_draft · unverified_draft
### cold-trpm8-universal-receptor M8-B affected all thermoeffectors studied, including thermal preference, tail-skin vasoconstriction and brown fat thermogenesis, suggesting that TRPM8 is a universal cold receptor in the thermoregulation system, and it attenuated cold-induced c-Fos expression in the lateral parabrachial nucleus. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The same sensor feeds every cold defence: behaviour, blood vessels and heat production. organism: Rat, mouse and human channels in vitro tissue_or_cell_type: Skin sensory neurons and thermoeffectors experimental_model: Rats and mice with a selective TRPM8 antagonist given by several routes limitations: On-target action is supported by the absence of effect in Trpm8-null mice. The peripheral site of action is inferred from route comparison, not from direct measurement at the nerve ending. exposure: M8-B intravenously, intrathecally or intracerebroventricularly, at constant or changing ambient temperature evidence_span: {"source_cache": "artifacts/cold-research/22323721.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "c0ead3b0097eaa75bf74d806e7f40bc61da4275cdd0af92735be9cad681ed3f0", "start_char": 0, "end_char": 1784, "text_sha256": "c0ead3b0097eaa75bf74d806e7f40bc61da4275cdd0af92735be9cad681ed3f0"} [cold-p22323721] Pharmacological blockade of the cold receptor TRPM8 attenuates autonomic and behavioral cold defenses and decreases deep body temperature. (2012). https://pubmed.ncbi.nlm.nih.gov/22323721/ DOI: 10.1523/jneurosci.5606-11.2012
Complete structured claim and evidence
A low intravenous dose did not affect body temperature at a constantly high or constantly low ambient temperature, but readily decreased it when rats were kept warm during infusion and transferred to cold immediately after, and below 23 degrees C tail-skin temperature the effect was inversely related to skin temperature.
Rate of fall of skin temperature → Core (rectal) body temperature source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/22323721.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "c0ead3b0097eaa75bf74d806e7f40bc61da4275cdd0af92735be9cad681ed3f0", "start_char": 0, "end_char": 1784, "text_sha256": "c0ead3b0097eaa75bf74d806e7f40bc61da4275cdd0af92735be9cad681ed3f0"}
experimental_model
Rats and mice with a selective TRPM8 antagonist given by several routes
exposure
M8-B intravenously, intrathecally or intracerebroventricularly, at constant or changing ambient temperature
limitations
On-target action is supported by the absence of effect in Trpm8-null mice. The peripheral site of action is inferred from route comparison, not from direct measurement at the nerve ending.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Rat, mouse and human channels in vitro
plain_language
The sensor only matters while the skin is actually cooling.
primary_references
[cold-p22323721] Pharmacological blockade of the cold receptor TRPM8 attenuates autonomic and behavioral cold defenses and decreases deep body temperature. (2012). https://pubmed.ncbi.nlm.nih.gov/22323721/ DOI: 10.1523/jneurosci.5606-11.2012
tissue_or_cell_type
Skin sensory neurons and thermoeffectors
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 117–128
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Rats and mice with a selective TRPM8 antagonist given by several routes · source_derived_draft · unverified_draft
### cold-trpm8-skin-delivery-requirement A low intravenous dose did not affect body temperature at a constantly high or constantly low ambient temperature, but readily decreased it when rats were kept warm during infusion and transferred to cold immediately after, and below 23 degrees C tail-skin temperature the effect was inversely related to skin temperature. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The sensor only matters while the skin is actually cooling. organism: Rat, mouse and human channels in vitro tissue_or_cell_type: Skin sensory neurons and thermoeffectors experimental_model: Rats and mice with a selective TRPM8 antagonist given by several routes limitations: On-target action is supported by the absence of effect in Trpm8-null mice. The peripheral site of action is inferred from route comparison, not from direct measurement at the nerve ending. exposure: M8-B intravenously, intrathecally or intracerebroventricularly, at constant or changing ambient temperature evidence_span: {"source_cache": "artifacts/cold-research/22323721.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "c0ead3b0097eaa75bf74d806e7f40bc61da4275cdd0af92735be9cad681ed3f0", "start_char": 0, "end_char": 1784, "text_sha256": "c0ead3b0097eaa75bf74d806e7f40bc61da4275cdd0af92735be9cad681ed3f0"} [cold-p22323721] Pharmacological blockade of the cold receptor TRPM8 attenuates autonomic and behavioral cold defenses and decreases deep body temperature. (2012). https://pubmed.ncbi.nlm.nih.gov/22323721/ DOI: 10.1523/jneurosci.5606-11.2012
Complete structured claim and evidence
The review concludes that the cold-shock response can result in death or serious incapacitation long before general hypothermia develops, and is probably responsible for the majority of annual open-water immersion deaths.
The cold shock response: inspiratory gasp, hyperventilation and tachycardia on immersion → Death during open-water immersion source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/2691172.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "f0ea32b8c041aaf1636ae487f2f557e600a778d5eb76bad44c2edfe70c368714", "start_char": 0, "end_char": 293, "text_sha256": "f0ea32b8c041aaf1636ae487f2f557e600a778d5eb76bad44c2edfe70c368714"}
experimental_model
Review of the initial responses to cold-water immersion and their role in immersion deaths
exposure
Sudden immersion in cold water
limitations
A narrative review, recorded as the framing source for the cold shock response. Its mortality attribution is an inference from the response, not a trial.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
The dangerous part of cold water is the first minute, not the slow chill.
primary_references
[cold-p2691172] The initial responses to cold-water immersion in man. (1989). https://pubmed.ncbi.nlm.nih.gov/2691172/ DOI: 10.1042/cs0770581
tissue_or_cell_type
Respiratory and cardiovascular system
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 130–141
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Review of the initial responses to cold-water immersion and their role in immersion deaths · source_derived_draft · unverified_draft
### cold-cold-shock-lethality The review concludes that the cold-shock response can result in death or serious incapacitation long before general hypothermia develops, and is probably responsible for the majority of annual open-water immersion deaths. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The dangerous part of cold water is the first minute, not the slow chill. organism: Human tissue_or_cell_type: Respiratory and cardiovascular system experimental_model: Review of the initial responses to cold-water immersion and their role in immersion deaths limitations: A narrative review, recorded as the framing source for the cold shock response. Its mortality attribution is an inference from the response, not a trial. exposure: Sudden immersion in cold water evidence_span: {"source_cache": "artifacts/cold-research/2691172.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "f0ea32b8c041aaf1636ae487f2f557e600a778d5eb76bad44c2edfe70c368714", "start_char": 0, "end_char": 293, "text_sha256": "f0ea32b8c041aaf1636ae487f2f557e600a778d5eb76bad44c2edfe70c368714"} [cold-p2691172] The initial responses to cold-water immersion in man. (1989). https://pubmed.ncbi.nlm.nih.gov/2691172/ DOI: 10.1042/cs0770581
Complete structured claim and evidence
Cold water submersion induces a high incidence of cardiac arrhythmias in healthy volunteers, and the authors propose that simultaneous activation of the sympathetically driven cold shock tachycardia and the parasympathetically mediated diving bradycardia accounts for them, and in vulnerable individuals may be responsible for deaths previously ascribed to drowning or hypothermia.
Simultaneous sympathetic and parasympathetic activation on cold submersion → Cardiac arrhythmia during cold water submersion source_derived_draftungraded
Experimental context and source evidence
availability_state
biomarker_context Imported condition classification; unverified.
evidence_span
{"source_cache": "artifacts/cold-research/22547634.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "c712f8554b0d375f87dfe68d4a5c33eb7b485e17953dd8e7bd4b2a1c1e700ee6", "start_char": 0, "end_char": 947, "text_sha256": "c712f8554b0d375f87dfe68d4a5c33eb7b485e17953dd8e7bd4b2a1c1e700ee6"}
experimental_model
Review proposing simultaneous activation of two antagonistic autonomic responses
exposure
Cold submersion with breath holding and its release
limitations
A hypothesis paper. The arrhythmia observations are from healthy volunteers; the attribution of deaths to autonomic conflict is explicitly proposed rather than demonstrated.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Two opposite nerve signals fire at once and the heart rhythm breaks down.
primary_references
[cold-p22547634] 'Autonomic conflict': a different way to die during cold water immersion? (2012). https://pubmed.ncbi.nlm.nih.gov/22547634/ DOI: 10.1113/jphysiol.2012.229864
tissue_or_cell_type
Heart
trigger_kind
biomarker_context Imported condition classification; unverified.
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 143–154
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Review proposing simultaneous activation of two antagonistic autonomic responses · source_derived_draft · unverified_draft
### cold-autonomic-conflict-arrhythmia Cold water submersion induces a high incidence of cardiac arrhythmias in healthy volunteers, and the authors propose that simultaneous activation of the sympathetically driven cold shock tachycardia and the parasympathetically mediated diving bradycardia accounts for them, and in vulnerable individuals may be responsible for deaths previously ascribed to drowning or hypothermia. Condition category: biomarker_context nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Two opposite nerve signals fire at once and the heart rhythm breaks down. organism: Human tissue_or_cell_type: Heart experimental_model: Review proposing simultaneous activation of two antagonistic autonomic responses limitations: A hypothesis paper. The arrhythmia observations are from healthy volunteers; the attribution of deaths to autonomic conflict is explicitly proposed rather than demonstrated. exposure: Cold submersion with breath holding and its release evidence_span: {"source_cache": "artifacts/cold-research/22547634.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "c712f8554b0d375f87dfe68d4a5c33eb7b485e17953dd8e7bd4b2a1c1e700ee6", "start_char": 0, "end_char": 947, "text_sha256": "c712f8554b0d375f87dfe68d4a5c33eb7b485e17953dd8e7bd4b2a1c1e700ee6"} [cold-p22547634] 'Autonomic conflict': a different way to die during cold water immersion? (2012). https://pubmed.ncbi.nlm.nih.gov/22547634/ DOI: 10.1113/jphysiol.2012.229864
Complete structured claim and evidence
Repeated immersions of one body side reduced heart rate and respiratory frequency and volume responses, and reduced the responses evoked on the opposite, previously unhabituated side, despite identical skin temperature profiles, placing the habituation mechanism more centrally than the peripheral receptors.
Habituation of the initial responses to cold water immersion → The cold shock response: inspiratory gasp, hyperventilation and tachycardia on immersion source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/9763650.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "0f007b123776a775f6672afa5075a3085c9ddb82578ad6b8984d3da95efbfd47", "start_char": 0, "end_char": 1204, "text_sha256": "0f007b123776a775f6672afa5075a3085c9ddb82578ad6b8984d3da95efbfd47"}
experimental_model
Two groups immersing contralateral body sides in stirred water at 10 degrees C
exposure
Two 3-minute head-out immersions at 10 degrees C, with six further immersions of the opposite side between them
limitations
A crossed-side design that separates central from peripheral habituation. Skin temperature profiles were identical between groups, which is what makes the conclusion interpretable.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Practising on one side of the body calms the response on the other, so the adaptation is in the brain, not the skin.
primary_references
[cold-p9763650] Habituation of the initial responses to cold water immersion in humans: a central or peripheral mechanism? (1998). https://pubmed.ncbi.nlm.nih.gov/9763650/ DOI: 10.1111/j.1469-7793.1998.621be.x
tissue_or_cell_type
Whole body
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 156–167
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Two groups immersing contralateral body sides in stirred water at 10 degrees C · source_derived_draft · unverified_draft
### cold-habituation-central Repeated immersions of one body side reduced heart rate and respiratory frequency and volume responses, and reduced the responses evoked on the opposite, previously unhabituated side, despite identical skin temperature profiles, placing the habituation mechanism more centrally than the peripheral receptors. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Practising on one side of the body calms the response on the other, so the adaptation is in the brain, not the skin. organism: Human tissue_or_cell_type: Whole body experimental_model: Two groups immersing contralateral body sides in stirred water at 10 degrees C limitations: A crossed-side design that separates central from peripheral habituation. Skin temperature profiles were identical between groups, which is what makes the conclusion interpretable. exposure: Two 3-minute head-out immersions at 10 degrees C, with six further immersions of the opposite side between them evidence_span: {"source_cache": "artifacts/cold-research/9763650.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "0f007b123776a775f6672afa5075a3085c9ddb82578ad6b8984d3da95efbfd47", "start_char": 0, "end_char": 1204, "text_sha256": "0f007b123776a775f6672afa5075a3085c9ddb82578ad6b8984d3da95efbfd47"} [cold-p9763650] Habituation of the initial responses to cold water immersion in humans: a central or peripheral mechanism? (1998). https://pubmed.ncbi.nlm.nih.gov/9763650/ DOI: 10.1111/j.1469-7793.1998.621be.x
Complete structured claim and evidence
Immersion at thermoneutral 32 degrees C did not change rectal temperature or metabolic rate but lowered heart rate by 15% and blood pressure by 11 to 12%, lowered plasma renin activity by 46%, cortisol by 34% and aldosterone by 17%, and increased diuresis by 107%.
Hydrostatic pressure of head-out water immersion, separate from its temperature → Urine output / diuresis source_derived_draftungraded
Experimental context and source evidence
evidence_span
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experimental_model
Young men during 1-hour head-out immersions at 32, 20 and 14 degrees C
exposure
One hour head-out immersion at three water temperatures
limitations
The thermoneutral arm separates hydrostatic pressure from cold. Cortisol did not rise at any temperature, which bears directly on calling immersion a stress response.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Simply being in water, at any temperature, drops blood pressure and makes you urinate.
primary_references
[cold-p10751106] Human physiological responses to immersion into water of different temperatures. (2000). https://pubmed.ncbi.nlm.nih.gov/10751106/ DOI: 10.1007/s004210050065
tissue_or_cell_type
Whole body
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 169–180
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Young men during 1-hour head-out immersions at 32, 20 and 14 degrees C · source_derived_draft · unverified_draft
### cold-pressure-versus-cold Immersion at thermoneutral 32 degrees C did not change rectal temperature or metabolic rate but lowered heart rate by 15% and blood pressure by 11 to 12%, lowered plasma renin activity by 46%, cortisol by 34% and aldosterone by 17%, and increased diuresis by 107%. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Simply being in water, at any temperature, drops blood pressure and makes you urinate. organism: Human tissue_or_cell_type: Whole body experimental_model: Young men during 1-hour head-out immersions at 32, 20 and 14 degrees C limitations: The thermoneutral arm separates hydrostatic pressure from cold. Cortisol did not rise at any temperature, which bears directly on calling immersion a stress response. exposure: One hour head-out immersion at three water temperatures evidence_span: {"source_cache": "artifacts/cold-research/10751106.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "d018fda7c67dc61bb0d4a38ddfd7850e7252897587c5a4477607271b10d42291", "start_char": 0, "end_char": 2332, "text_sha256": "d018fda7c67dc61bb0d4a38ddfd7850e7252897587c5a4477607271b10d42291"} [cold-p10751106] Human physiological responses to immersion into water of different temperatures. (2000). https://pubmed.ncbi.nlm.nih.gov/10751106/ DOI: 10.1007/s004210050065
Complete structured claim and evidence
Immersion at 14 degrees C lowered rectal temperature and increased metabolic rate by 350%, with heart rate and systolic and diastolic blood pressure rising by 5, 7 and 8%.
Cold water immersion → Whole-body metabolic rate source_derived_draftungraded
Experimental context and source evidence
evidence_span
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experimental_model
Young men during 1-hour head-out immersions at 32, 20 and 14 degrees C
exposure
One hour head-out immersion at three water temperatures
limitations
The thermoneutral arm separates hydrostatic pressure from cold. Cortisol did not rise at any temperature, which bears directly on calling immersion a stress response.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
At 14 degrees the body burns roughly four and a half times as much energy as at rest.
primary_references
[cold-p10751106] Human physiological responses to immersion into water of different temperatures. (2000). https://pubmed.ncbi.nlm.nih.gov/10751106/ DOI: 10.1007/s004210050065
tissue_or_cell_type
Whole body
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 182–193
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Young men during 1-hour head-out immersions at 32, 20 and 14 degrees C · source_derived_draft · unverified_draft
### cold-cold-metabolic-rate Immersion at 14 degrees C lowered rectal temperature and increased metabolic rate by 350%, with heart rate and systolic and diastolic blood pressure rising by 5, 7 and 8%. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: At 14 degrees the body burns roughly four and a half times as much energy as at rest. organism: Human tissue_or_cell_type: Whole body experimental_model: Young men during 1-hour head-out immersions at 32, 20 and 14 degrees C limitations: The thermoneutral arm separates hydrostatic pressure from cold. Cortisol did not rise at any temperature, which bears directly on calling immersion a stress response. exposure: One hour head-out immersion at three water temperatures evidence_span: {"source_cache": "artifacts/cold-research/10751106.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "d018fda7c67dc61bb0d4a38ddfd7850e7252897587c5a4477607271b10d42291", "start_char": 0, "end_char": 2332, "text_sha256": "d018fda7c67dc61bb0d4a38ddfd7850e7252897587c5a4477607271b10d42291"} [cold-p10751106] Human physiological responses to immersion into water of different temperatures. (2000). https://pubmed.ncbi.nlm.nih.gov/10751106/ DOI: 10.1007/s004210050065
Complete structured claim and evidence
Plasma noradrenaline and dopamine concentrations increased by 530% and 250% at 14 degrees C, while plasma adrenaline concentrations remained unchanged and cortisol tended to decrease.
Cold water immersion → Plasma noradrenaline concentration source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/10751106.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "d018fda7c67dc61bb0d4a38ddfd7850e7252897587c5a4477607271b10d42291", "start_char": 0, "end_char": 2332, "text_sha256": "d018fda7c67dc61bb0d4a38ddfd7850e7252897587c5a4477607271b10d42291"}
experimental_model
Young men during 1-hour head-out immersions at 32, 20 and 14 degrees C
exposure
One hour head-out immersion at three water temperatures
limitations
The thermoneutral arm separates hydrostatic pressure from cold. Cortisol did not rise at any temperature, which bears directly on calling immersion a stress response.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Cold water multiplies one messenger sixfold and leaves adrenaline and cortisol alone.
primary_references
[cold-p10751106] Human physiological responses to immersion into water of different temperatures. (2000). https://pubmed.ncbi.nlm.nih.gov/10751106/ DOI: 10.1007/s004210050065
tissue_or_cell_type
Whole body
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 195–206
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Young men during 1-hour head-out immersions at 32, 20 and 14 degrees C · source_derived_draft · unverified_draft
### cold-cold-noradrenaline-rise Plasma noradrenaline and dopamine concentrations increased by 530% and 250% at 14 degrees C, while plasma adrenaline concentrations remained unchanged and cortisol tended to decrease. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Cold water multiplies one messenger sixfold and leaves adrenaline and cortisol alone. organism: Human tissue_or_cell_type: Whole body experimental_model: Young men during 1-hour head-out immersions at 32, 20 and 14 degrees C limitations: The thermoneutral arm separates hydrostatic pressure from cold. Cortisol did not rise at any temperature, which bears directly on calling immersion a stress response. exposure: One hour head-out immersion at three water temperatures evidence_span: {"source_cache": "artifacts/cold-research/10751106.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "d018fda7c67dc61bb0d4a38ddfd7850e7252897587c5a4477607271b10d42291", "start_char": 0, "end_char": 2332, "text_sha256": "d018fda7c67dc61bb0d4a38ddfd7850e7252897587c5a4477607271b10d42291"} [cold-p10751106] Human physiological responses to immersion into water of different temperatures. (2000). https://pubmed.ncbi.nlm.nih.gov/10751106/ DOI: 10.1007/s004210050065
Complete structured claim and evidence
The authors concluded that physiological changes induced by water immersion are mediated by humoral control mechanisms, while responses induced by cold are mainly due to increased activity of the sympathetic nervous system, with no correlation between changes in rectal temperature and changes in hormone production.
Sympathetic nervous system activity → Whole-body metabolic rate source_derived_draftungraded
Experimental context and source evidence
evidence_span
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experimental_model
Young men during 1-hour head-out immersions at 32, 20 and 14 degrees C
exposure
One hour head-out immersion at three water temperatures
limitations
The thermoneutral arm separates hydrostatic pressure from cold. Cortisol did not rise at any temperature, which bears directly on calling immersion a stress response.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
The water effects and the cold effects travel by two different routes.
primary_references
[cold-p10751106] Human physiological responses to immersion into water of different temperatures. (2000). https://pubmed.ncbi.nlm.nih.gov/10751106/ DOI: 10.1007/s004210050065
tissue_or_cell_type
Whole body
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 208–219
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Young men during 1-hour head-out immersions at 32, 20 and 14 degrees C · source_derived_draft · unverified_draft
### cold-cold-sympathetic-attribution The authors concluded that physiological changes induced by water immersion are mediated by humoral control mechanisms, while responses induced by cold are mainly due to increased activity of the sympathetic nervous system, with no correlation between changes in rectal temperature and changes in hormone production. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The water effects and the cold effects travel by two different routes. organism: Human tissue_or_cell_type: Whole body experimental_model: Young men during 1-hour head-out immersions at 32, 20 and 14 degrees C limitations: The thermoneutral arm separates hydrostatic pressure from cold. Cortisol did not rise at any temperature, which bears directly on calling immersion a stress response. exposure: One hour head-out immersion at three water temperatures evidence_span: {"source_cache": "artifacts/cold-research/10751106.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "d018fda7c67dc61bb0d4a38ddfd7850e7252897587c5a4477607271b10d42291", "start_char": 0, "end_char": 2332, "text_sha256": "d018fda7c67dc61bb0d4a38ddfd7850e7252897587c5a4477607271b10d42291"} [cold-p10751106] Human physiological responses to immersion into water of different temperatures. (2000). https://pubmed.ncbi.nlm.nih.gov/10751106/ DOI: 10.1007/s004210050065
Complete structured claim and evidence
Index-finger cooling produced cold-induced vasodilatation earlier than hand or forearm immersion (5.90 versus 7.95 and 9.26 minutes) and without significant cardiovascular change, whereas hand or forearm immersion produced a delayed and slower vasodilatation with bradycardia at the end of the test and a larger blood pressure rise.
Cold water immersion → Cold-induced vasodilatation in the extremities source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/9202941.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "0c66741aac658e383d3e372a1c257db8dbcbce5e57d4dc053583181192f0c2e1", "start_char": 0, "end_char": 1846, "text_sha256": "0c66741aac658e383d3e372a1c257db8dbcbce5e57d4dc053583181192f0c2e1"}
experimental_model
Twenty subjects immersing finger, hand, or forearm and hand in 5 degrees C water
exposure
30 minutes of immersion at 5 degrees C followed by 15 minutes of recovery
limitations
The comparison of immersed areas is the point: the cardiovascular response depends on how much skin is cooled, not on the temperature alone.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
How much of you goes in the water decides what your heart and vessels do.
primary_references
[cold-p9202941] Cold induced vasodilatation and cardiovascular responses in humans during cold water immersion of various upper limb areas. (1997). https://pubmed.ncbi.nlm.nih.gov/9202941/ DOI: 10.1007/s004210050191
tissue_or_cell_type
Upper limb skin and cardiovascular system
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 221–232
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Twenty subjects immersing finger, hand, or forearm and hand in 5 degrees C water · source_derived_draft · unverified_draft
### cold-civd-area-dependence Index-finger cooling produced cold-induced vasodilatation earlier than hand or forearm immersion (5.90 versus 7.95 and 9.26 minutes) and without significant cardiovascular change, whereas hand or forearm immersion produced a delayed and slower vasodilatation with bradycardia at the end of the test and a larger blood pressure rise. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: How much of you goes in the water decides what your heart and vessels do. organism: Human tissue_or_cell_type: Upper limb skin and cardiovascular system experimental_model: Twenty subjects immersing finger, hand, or forearm and hand in 5 degrees C water limitations: The comparison of immersed areas is the point: the cardiovascular response depends on how much skin is cooled, not on the temperature alone. exposure: 30 minutes of immersion at 5 degrees C followed by 15 minutes of recovery evidence_span: {"source_cache": "artifacts/cold-research/9202941.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "0c66741aac658e383d3e372a1c257db8dbcbce5e57d4dc053583181192f0c2e1", "start_char": 0, "end_char": 1846, "text_sha256": "0c66741aac658e383d3e372a1c257db8dbcbce5e57d4dc053583181192f0c2e1"} [cold-p9202941] Cold induced vasodilatation and cardiovascular responses in humans during cold water immersion of various upper limb areas. (1997). https://pubmed.ncbi.nlm.nih.gov/9202941/ DOI: 10.1007/s004210050191
Complete structured claim and evidence
The initial cold-induced vasoconstriction involved constriction of the arteriovenous anastomoses and the two main finger arteries, and during cold-induced vasodilatation the large blood flow and high skin temperature were caused by relaxation of the smooth muscle cells of the arteriovenous anastomoses, with velocity fluctuations synchronous with the uncooled control finger.
Arteriovenous anastomoses of the finger → Cold-induced vasodilatation in the extremities source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/10070133.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "645f4eccd5fc06bd968b4fddd514e55561f4403ec1c2e3437beae785c006e19f", "start_char": 0, "end_char": 1121, "text_sha256": "645f4eccd5fc06bd968b4fddd514e55561f4403ec1c2e3437beae785c006e19f"}
experimental_model
Ultrasound Doppler of finger arteries during severe local cooling in 21 thermoneutral subjects
exposure
Local cooling at 3 degrees C for 30 to 45 minutes
limitations
Direct vessel-level measurement. It identifies which vessels open, and the synchrony with the control finger indicates central rather than purely local control.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Specific shunt vessels clamp shut and then open again, and both hands do it together.
primary_references
[cold-p10070133] Perfusion of the human finger during cold-induced vasodilatation. (1999). https://pubmed.ncbi.nlm.nih.gov/10070133/ DOI: 10.1152/ajpregu.1999.276.3.r731
tissue_or_cell_type
Finger arteries and arteriovenous anastomoses
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 234–245
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Ultrasound Doppler of finger arteries during severe local cooling in 21 thermoneutral subjects · source_derived_draft · unverified_draft
### cold-civd-ava-mechanism The initial cold-induced vasoconstriction involved constriction of the arteriovenous anastomoses and the two main finger arteries, and during cold-induced vasodilatation the large blood flow and high skin temperature were caused by relaxation of the smooth muscle cells of the arteriovenous anastomoses, with velocity fluctuations synchronous with the uncooled control finger. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Specific shunt vessels clamp shut and then open again, and both hands do it together. organism: Human tissue_or_cell_type: Finger arteries and arteriovenous anastomoses experimental_model: Ultrasound Doppler of finger arteries during severe local cooling in 21 thermoneutral subjects limitations: Direct vessel-level measurement. It identifies which vessels open, and the synchrony with the control finger indicates central rather than purely local control. exposure: Local cooling at 3 degrees C for 30 to 45 minutes evidence_span: {"source_cache": "artifacts/cold-research/10070133.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "645f4eccd5fc06bd968b4fddd514e55561f4403ec1c2e3437beae785c006e19f", "start_char": 0, "end_char": 1121, "text_sha256": "645f4eccd5fc06bd968b4fddd514e55561f4403ec1c2e3437beae785c006e19f"} [cold-p10070133] Perfusion of the human finger during cold-induced vasodilatation. (1999). https://pubmed.ncbi.nlm.nih.gov/10070133/ DOI: 10.1152/ajpregu.1999.276.3.r731
Complete structured claim and evidence
Brown adipose tissue activity was observed in 23 of 24 subjects during cold exposure at 16 degrees C but not under thermoneutral conditions.
Brown adipose tissue → Brown adipose tissue glucose uptake source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/19357405.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "fc69ba9ec6aa4e295cde530497a3ef435ad5fa436888932b81565c05eb4ecf67", "start_char": 0, "end_char": 2035, "text_sha256": "fc69ba9ec6aa4e295cde530497a3ef435ad5fa436888932b81565c05eb4ecf67"}
experimental_model
Twenty-four lean and overweight healthy men studied by integrated FDG PET and CT
exposure
Thermoneutral 22 degrees C versus mild cold exposure at 16 degrees C
limitations
A systematic human survey establishing that the tissue is present and cold-activated. Glucose uptake on PET is an activity surrogate, not a heat measurement.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Nearly every young adult has this tissue, and only cold switches it on.
primary_references
[cold-p19357405] Cold-activated brown adipose tissue in healthy men. (2009). https://pubmed.ncbi.nlm.nih.gov/19357405/ DOI: 10.1056/nejmoa0808718
tissue_or_cell_type
Supraclavicular and paravertebral brown adipose tissue
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 247–258
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Twenty-four lean and overweight healthy men studied by integrated FDG PET and CT · source_derived_draft · unverified_draft
### cold-bat-present-in-adults Brown adipose tissue activity was observed in 23 of 24 subjects during cold exposure at 16 degrees C but not under thermoneutral conditions. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Nearly every young adult has this tissue, and only cold switches it on. organism: Human tissue_or_cell_type: Supraclavicular and paravertebral brown adipose tissue experimental_model: Twenty-four lean and overweight healthy men studied by integrated FDG PET and CT limitations: A systematic human survey establishing that the tissue is present and cold-activated. Glucose uptake on PET is an activity surrogate, not a heat measurement. exposure: Thermoneutral 22 degrees C versus mild cold exposure at 16 degrees C evidence_span: {"source_cache": "artifacts/cold-research/19357405.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "fc69ba9ec6aa4e295cde530497a3ef435ad5fa436888932b81565c05eb4ecf67", "start_char": 0, "end_char": 2035, "text_sha256": "fc69ba9ec6aa4e295cde530497a3ef435ad5fa436888932b81565c05eb4ecf67"} [cold-p19357405] Cold-activated brown adipose tissue in healthy men. (2009). https://pubmed.ncbi.nlm.nih.gov/19357405/ DOI: 10.1056/nejmoa0808718
Complete structured claim and evidence
Cold-activated brown adipose tissue activity was significantly lower in overweight or obese subjects than in lean subjects, with body-mass index and percentage body fat both negatively correlated and resting metabolic rate positively correlated.
Brown adipose tissue glucose uptake → Body fat mass source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/19357405.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "fc69ba9ec6aa4e295cde530497a3ef435ad5fa436888932b81565c05eb4ecf67", "start_char": 0, "end_char": 2035, "text_sha256": "fc69ba9ec6aa4e295cde530497a3ef435ad5fa436888932b81565c05eb4ecf67"}
experimental_model
Twenty-four lean and overweight healthy men studied by integrated FDG PET and CT
exposure
Thermoneutral 22 degrees C versus mild cold exposure at 16 degrees C
limitations
A systematic human survey establishing that the tissue is present and cold-activated. Glucose uptake on PET is an activity surrogate, not a heat measurement.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
The people with more fat had less of the tissue that burns it.
primary_references
[cold-p19357405] Cold-activated brown adipose tissue in healthy men. (2009). https://pubmed.ncbi.nlm.nih.gov/19357405/ DOI: 10.1056/nejmoa0808718
tissue_or_cell_type
Supraclavicular and paravertebral brown adipose tissue
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 260–271
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Twenty-four lean and overweight healthy men studied by integrated FDG PET and CT · source_derived_draft · unverified_draft
### cold-bat-inverse-adiposity Cold-activated brown adipose tissue activity was significantly lower in overweight or obese subjects than in lean subjects, with body-mass index and percentage body fat both negatively correlated and resting metabolic rate positively correlated. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The people with more fat had less of the tissue that burns it. organism: Human tissue_or_cell_type: Supraclavicular and paravertebral brown adipose tissue experimental_model: Twenty-four lean and overweight healthy men studied by integrated FDG PET and CT limitations: A systematic human survey establishing that the tissue is present and cold-activated. Glucose uptake on PET is an activity surrogate, not a heat measurement. exposure: Thermoneutral 22 degrees C versus mild cold exposure at 16 degrees C evidence_span: {"source_cache": "artifacts/cold-research/19357405.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "fc69ba9ec6aa4e295cde530497a3ef435ad5fa436888932b81565c05eb4ecf67", "start_char": 0, "end_char": 2035, "text_sha256": "fc69ba9ec6aa4e295cde530497a3ef435ad5fa436888932b81565c05eb4ecf67"} [cold-p19357405] Cold-activated brown adipose tissue in healthy men. (2009). https://pubmed.ncbi.nlm.nih.gov/19357405/ DOI: 10.1056/nejmoa0808718
Complete structured claim and evidence
Cold exposure activated oxidative metabolism in brown adipose tissue but not in adjoining skeletal muscle or subcutaneous adipose tissue, with substantial non-esterified fatty acid and glucose uptake, and this was associated with an increase in total energy expenditure.
Brown adipose tissue → Brown adipose tissue oxidative metabolism source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/22269323.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "74713401a7fdc40f7921b595ecc554999d10e2406589f231fc68bf0ae460812f", "start_char": 0, "end_char": 1306, "text_sha256": "74713401a7fdc40f7921b595ecc554999d10e2406589f231fc68bf0ae460812f"}
experimental_model
Six healthy men studied with 11C-acetate, 18FDG and a fatty acid tracer under controlled cold
exposure
Controlled cold exposure with quantified oxidative metabolism and substrate turnover
limitations
The acetate tracer measures oxidative metabolism rather than glucose uptake alone, which is what makes the thermogenic claim interpretable. Six subjects is a small sample.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
The tissue really does burn fuel in the cold, and its neighbours do not.
primary_references
[cold-p22269323] Brown adipose tissue oxidative metabolism contributes to energy expenditure during acute cold exposure in humans. (2012). https://pubmed.ncbi.nlm.nih.gov/22269323/ DOI: 10.1172/jci60433
tissue_or_cell_type
Brown adipose tissue, skeletal muscle and subcutaneous fat
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 273–284
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Six healthy men studied with 11C-acetate, 18FDG and a fatty acid tracer under controlled cold · source_derived_draft · unverified_draft
### cold-bat-oxidative-activation Cold exposure activated oxidative metabolism in brown adipose tissue but not in adjoining skeletal muscle or subcutaneous adipose tissue, with substantial non-esterified fatty acid and glucose uptake, and this was associated with an increase in total energy expenditure. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The tissue really does burn fuel in the cold, and its neighbours do not. organism: Human tissue_or_cell_type: Brown adipose tissue, skeletal muscle and subcutaneous fat experimental_model: Six healthy men studied with 11C-acetate, 18FDG and a fatty acid tracer under controlled cold limitations: The acetate tracer measures oxidative metabolism rather than glucose uptake alone, which is what makes the thermogenic claim interpretable. Six subjects is a small sample. exposure: Controlled cold exposure with quantified oxidative metabolism and substrate turnover evidence_span: {"source_cache": "artifacts/cold-research/22269323.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "74713401a7fdc40f7921b595ecc554999d10e2406589f231fc68bf0ae460812f", "start_char": 0, "end_char": 1306, "text_sha256": "74713401a7fdc40f7921b595ecc554999d10e2406589f231fc68bf0ae460812f"} [cold-p22269323] Brown adipose tissue oxidative metabolism contributes to energy expenditure during acute cold exposure in humans. (2012). https://pubmed.ncbi.nlm.nih.gov/22269323/ DOI: 10.1172/jci60433
Complete structured claim and evidence
An inverse relationship was found between brown adipose tissue activity and shivering, and brown adipose tissue radio density increased upon cold exposure, indicating reduced triglyceride content.
Brown adipose tissue oxidative metabolism → Shivering thermogenesis source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/22269323.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "74713401a7fdc40f7921b595ecc554999d10e2406589f231fc68bf0ae460812f", "start_char": 0, "end_char": 1306, "text_sha256": "74713401a7fdc40f7921b595ecc554999d10e2406589f231fc68bf0ae460812f"}
experimental_model
Six healthy men studied with 11C-acetate, 18FDG and a fatty acid tracer under controlled cold
exposure
Controlled cold exposure with quantified oxidative metabolism and substrate turnover
limitations
The acetate tracer measures oxidative metabolism rather than glucose uptake alone, which is what makes the thermogenic claim interpretable. Six subjects is a small sample.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
The more this tissue works, the less you shiver, and it visibly uses up its own fat.
primary_references
[cold-p22269323] Brown adipose tissue oxidative metabolism contributes to energy expenditure during acute cold exposure in humans. (2012). https://pubmed.ncbi.nlm.nih.gov/22269323/ DOI: 10.1172/jci60433
tissue_or_cell_type
Brown adipose tissue, skeletal muscle and subcutaneous fat
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 286–297
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Six healthy men studied with 11C-acetate, 18FDG and a fatty acid tracer under controlled cold · source_derived_draft · unverified_draft
### cold-bat-shivering-inverse An inverse relationship was found between brown adipose tissue activity and shivering, and brown adipose tissue radio density increased upon cold exposure, indicating reduced triglyceride content. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The more this tissue works, the less you shiver, and it visibly uses up its own fat. organism: Human tissue_or_cell_type: Brown adipose tissue, skeletal muscle and subcutaneous fat experimental_model: Six healthy men studied with 11C-acetate, 18FDG and a fatty acid tracer under controlled cold limitations: The acetate tracer measures oxidative metabolism rather than glucose uptake alone, which is what makes the thermogenic claim interpretable. Six subjects is a small sample. exposure: Controlled cold exposure with quantified oxidative metabolism and substrate turnover evidence_span: {"source_cache": "artifacts/cold-research/22269323.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "74713401a7fdc40f7921b595ecc554999d10e2406589f231fc68bf0ae460812f", "start_char": 0, "end_char": 1306, "text_sha256": "74713401a7fdc40f7921b595ecc554999d10e2406589f231fc68bf0ae460812f"} [cold-p22269323] Brown adipose tissue oxidative metabolism contributes to energy expenditure during acute cold exposure in humans. (2012). https://pubmed.ncbi.nlm.nih.gov/22269323/ DOI: 10.1172/jci60433
Complete structured claim and evidence
Cold induced a 12-fold increase in brown adipose tissue glucose uptake accompanied by a doubling of perfusion, with whole-body energy expenditure positively associated with perfusion, whereas insulin enhanced glucose uptake 5-fold independently of perfusion.
Brown adipose tissue → Brown adipose tissue perfusion source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/21803297.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "59c9610242aa276de795dd00e2855d10444505f6005a87b85bc058cd564a7e52", "start_char": 0, "end_char": 997, "text_sha256": "59c9610242aa276de795dd00e2855d10444505f6005a87b85bc058cd564a7e52"}
experimental_model
PET-CT of glucose uptake and perfusion in human brown and white adipose tissue with gene expression
exposure
Cold activation compared with insulin stimulation
limitations
The cold and insulin arms are separated deliberately, which shows the tissue has two distinct activation modes.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Cold makes the tissue take up fuel and open its blood supply; insulin only does the first.
primary_references
[cold-p21803297] Different metabolic responses of human brown adipose tissue to activation by cold and insulin. (2011). https://pubmed.ncbi.nlm.nih.gov/21803297/ DOI: 10.1016/j.cmet.2011.06.012
tissue_or_cell_type
Brown and white adipose tissue
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 299–310
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · PET-CT of glucose uptake and perfusion in human brown and white adipose tissue with gene expression · source_derived_draft · unverified_draft
### cold-bat-cold-versus-insulin Cold induced a 12-fold increase in brown adipose tissue glucose uptake accompanied by a doubling of perfusion, with whole-body energy expenditure positively associated with perfusion, whereas insulin enhanced glucose uptake 5-fold independently of perfusion. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Cold makes the tissue take up fuel and open its blood supply; insulin only does the first. organism: Human tissue_or_cell_type: Brown and white adipose tissue experimental_model: PET-CT of glucose uptake and perfusion in human brown and white adipose tissue with gene expression limitations: The cold and insulin arms are separated deliberately, which shows the tissue has two distinct activation modes. exposure: Cold activation compared with insulin stimulation evidence_span: {"source_cache": "artifacts/cold-research/21803297.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "59c9610242aa276de795dd00e2855d10444505f6005a87b85bc058cd564a7e52", "start_char": 0, "end_char": 997, "text_sha256": "59c9610242aa276de795dd00e2855d10444505f6005a87b85bc058cd564a7e52"} [cold-p21803297] Different metabolic responses of human brown adipose tissue to activation by cold and insulin. (2011). https://pubmed.ncbi.nlm.nih.gov/21803297/ DOI: 10.1016/j.cmet.2011.06.012
Complete structured claim and evidence
UCP1-ablated mice acclimated to 4 degrees C sustained heat production at four times resting levels entirely by shivering, with no substitution by any adaptive non-shivering thermogenic process in muscle or any other organ, and neither UCP2 nor UCP3 could substitute.
Human mitochondrial uncoupling protein 1 / UCP1 → Non-shivering thermogenesis source_derived_draftungraded
Experimental context and source evidence
availability_state
machinery_impairment Imported condition classification; unverified.
evidence_span
{"source_cache": "artifacts/cold-research/11511509.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "6e49074478632e22aff36d236fa55e5afb956a4b335f7d95d2cae6f02c4f3d05", "start_char": 0, "end_char": 1527, "text_sha256": "6e49074478632e22aff36d236fa55e5afb956a4b335f7d95d2cae6f02c4f3d05"}
experimental_model
UCP1-ablated mice acclimated successively to 4 degrees C
exposure
Successive cold acclimation with heat production at four times resting level
limitations
A demanding negative result: no substitute for the protein was recruited even under extreme thermogenic demand. It is a mouse result about adaptive non-shivering thermogenesis specifically.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Mouse
plain_language
Only one protein can produce adaptive heat without shivering; nothing else stands in for it.
primary_references
[cold-p11511509] Only UCP1 can mediate adaptive nonshivering thermogenesis in the cold. (2001). https://pubmed.ncbi.nlm.nih.gov/11511509/ DOI: 10.1096/fj.00-0536fje
tissue_or_cell_type
Brown adipose tissue, muscle and whole body
trigger_kind
machinery_impairment Imported condition classification; unverified.
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 312–323
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · UCP1-ablated mice acclimated successively to 4 degrees C · source_derived_draft · unverified_draft
### cold-ucp1-only-mediator UCP1-ablated mice acclimated to 4 degrees C sustained heat production at four times resting levels entirely by shivering, with no substitution by any adaptive non-shivering thermogenic process in muscle or any other organ, and neither UCP2 nor UCP3 could substitute. Condition category: machinery_impairment nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Only one protein can produce adaptive heat without shivering; nothing else stands in for it. organism: Mouse tissue_or_cell_type: Brown adipose tissue, muscle and whole body experimental_model: UCP1-ablated mice acclimated successively to 4 degrees C limitations: A demanding negative result: no substitute for the protein was recruited even under extreme thermogenic demand. It is a mouse result about adaptive non-shivering thermogenesis specifically. exposure: Successive cold acclimation with heat production at four times resting level evidence_span: {"source_cache": "artifacts/cold-research/11511509.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "6e49074478632e22aff36d236fa55e5afb956a4b335f7d95d2cae6f02c4f3d05", "start_char": 0, "end_char": 1527, "text_sha256": "6e49074478632e22aff36d236fa55e5afb956a4b335f7d95d2cae6f02c4f3d05"} [cold-p11511509] Only UCP1 can mediate adaptive nonshivering thermogenesis in the cold. (2001). https://pubmed.ncbi.nlm.nih.gov/11511509/ DOI: 10.1096/fj.00-0536fje
Complete structured claim and evidence
At thermoneutrality, UCP1 ablation induced obesity even on control diet and vastly augmented diet-induced obesity, and high-fat diet increased norepinephrine-induced thermogenesis in wild-type but not UCP1-ablated mice, showing diet-induced thermogenesis fully emanates from UCP1 activity.
Experimental UCP1-ablated mouse genotype → Body fat mass source_derived_draftungraded
Experimental context and source evidence
availability_state
machinery_impairment Imported condition classification; unverified.
evidence_span
{"source_cache": "artifacts/cold-research/19187776.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "007fc44fbc02ff64861f816e90139d469f59bbe7d95bd22c6e4daecd38070b30", "start_char": 0, "end_char": 1051, "text_sha256": "007fc44fbc02ff64861f816e90139d469f59bbe7d95bd22c6e4daecd38070b30"}
experimental_model
UCP1-ablated C57Bl6 mice housed at thermoneutrality on control or high-fat diet
exposure
Thermoneutral housing with control and high-fat diets
limitations
Housing temperature is the whole point: the obesogenic effect appears only when thermal stress is removed. Earlier studies missed it for that reason.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Mouse
plain_language
Remove the heat protein and take away the cold, and the animal gets fat.
primary_references
[cold-p19187776] UCP1 ablation induces obesity and abolishes diet-induced thermogenesis in mice exempt from thermal stress by living at thermoneutrality. (2009). https://pubmed.ncbi.nlm.nih.gov/19187776/ DOI: 10.1016/j.cmet.2008.12.014
tissue_or_cell_type
Brown adipose tissue and whole body
trigger_kind
machinery_impairment Imported condition classification; unverified.
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 325–336
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · UCP1-ablated C57Bl6 mice housed at thermoneutrality on control or high-fat diet · source_derived_draft · unverified_draft
### cold-ucp1-ablation-obesity At thermoneutrality, UCP1 ablation induced obesity even on control diet and vastly augmented diet-induced obesity, and high-fat diet increased norepinephrine-induced thermogenesis in wild-type but not UCP1-ablated mice, showing diet-induced thermogenesis fully emanates from UCP1 activity. Condition category: machinery_impairment nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Remove the heat protein and take away the cold, and the animal gets fat. organism: Mouse tissue_or_cell_type: Brown adipose tissue and whole body experimental_model: UCP1-ablated C57Bl6 mice housed at thermoneutrality on control or high-fat diet limitations: Housing temperature is the whole point: the obesogenic effect appears only when thermal stress is removed. Earlier studies missed it for that reason. exposure: Thermoneutral housing with control and high-fat diets evidence_span: {"source_cache": "artifacts/cold-research/19187776.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "007fc44fbc02ff64861f816e90139d469f59bbe7d95bd22c6e4daecd38070b30", "start_char": 0, "end_char": 1051, "text_sha256": "007fc44fbc02ff64861f816e90139d469f59bbe7d95bd22c6e4daecd38070b30"} [cold-p19187776] UCP1 ablation induces obesity and abolishes diet-induced thermogenesis in mice exempt from thermal stress by living at thermoneutrality. (2009). https://pubmed.ncbi.nlm.nih.gov/19187776/ DOI: 10.1016/j.cmet.2008.12.014
Complete structured claim and evidence
PGC-1 mRNA expression is dramatically elevated on cold exposure in both brown fat and skeletal muscle, and PGC-1 greatly increases the transcriptional activity of PPARgamma and the thyroid hormone receptor on the UCP1 promoter.
Human PGC-1alpha transcriptional coactivator / PPARGC1A → Transcriptional activity at the UCP1 promoter source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/9529258.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "8986da918d7bde4d0314f51038ee3b1c6413042a1132bb6fbf55ceeb54e79ddf", "start_char": 0, "end_char": 842, "text_sha256": "8986da918d7bde4d0314f51038ee3b1c6413042a1132bb6fbf55ceeb54e79ddf"}
experimental_model
Cloning of PGC-1 from a brown fat cDNA library with ectopic expression in white adipose cells
exposure
Cold exposure of mice; ectopic PGC-1 expression
limitations
The founding description of the coactivator. Ectopic expression shows sufficiency in white fat cells; it does not establish the size of the contribution in vivo.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Mouse
plain_language
Cold turns on a coactivator that switches the heat gene on through two different receptors.
primary_references
[cold-p9529258] A cold-inducible coactivator of nuclear receptors linked to adaptive thermogenesis. (1998). https://pubmed.ncbi.nlm.nih.gov/9529258/ DOI: 10.1016/s0092-8674(00)81410-5
tissue_or_cell_type
Brown fat and skeletal muscle
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 338–349
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Cloning of PGC-1 from a brown fat cDNA library with ectopic expression in white adipose cells · source_derived_draft · unverified_draft
### cold-pgc1a-cold-induction PGC-1 mRNA expression is dramatically elevated on cold exposure in both brown fat and skeletal muscle, and PGC-1 greatly increases the transcriptional activity of PPARgamma and the thyroid hormone receptor on the UCP1 promoter. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Cold turns on a coactivator that switches the heat gene on through two different receptors. organism: Mouse tissue_or_cell_type: Brown fat and skeletal muscle experimental_model: Cloning of PGC-1 from a brown fat cDNA library with ectopic expression in white adipose cells limitations: The founding description of the coactivator. Ectopic expression shows sufficiency in white fat cells; it does not establish the size of the contribution in vivo. exposure: Cold exposure of mice; ectopic PGC-1 expression evidence_span: {"source_cache": "artifacts/cold-research/9529258.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "8986da918d7bde4d0314f51038ee3b1c6413042a1132bb6fbf55ceeb54e79ddf", "start_char": 0, "end_char": 842, "text_sha256": "8986da918d7bde4d0314f51038ee3b1c6413042a1132bb6fbf55ceeb54e79ddf"} [cold-p9529258] A cold-inducible coactivator of nuclear receptors linked to adaptive thermogenesis. (1998). https://pubmed.ncbi.nlm.nih.gov/9529258/ DOI: 10.1016/s0092-8674(00)81410-5
Complete structured claim and evidence
Ectopic expression of PGC-1 in white adipose cells activated expression of UCP1 and key mitochondrial enzymes of the respiratory chain, and increased cellular mitochondrial DNA content.
Human PGC-1alpha transcriptional coactivator / PPARGC1A → Cellular mitochondrial DNA content source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/9529258.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "8986da918d7bde4d0314f51038ee3b1c6413042a1132bb6fbf55ceeb54e79ddf", "start_char": 0, "end_char": 842, "text_sha256": "8986da918d7bde4d0314f51038ee3b1c6413042a1132bb6fbf55ceeb54e79ddf"}
experimental_model
Cloning of PGC-1 from a brown fat cDNA library with ectopic expression in white adipose cells
exposure
Cold exposure of mice; ectopic PGC-1 expression
limitations
The founding description of the coactivator. Ectopic expression shows sufficiency in white fat cells; it does not establish the size of the contribution in vivo.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Mouse
plain_language
The same switch builds more mitochondria to do the burning.
primary_references
[cold-p9529258] A cold-inducible coactivator of nuclear receptors linked to adaptive thermogenesis. (1998). https://pubmed.ncbi.nlm.nih.gov/9529258/ DOI: 10.1016/s0092-8674(00)81410-5
tissue_or_cell_type
Brown fat and skeletal muscle
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 351–362
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Cloning of PGC-1 from a brown fat cDNA library with ectopic expression in white adipose cells · source_derived_draft · unverified_draft
### cold-pgc1a-mitochondrial-biogenesis Ectopic expression of PGC-1 in white adipose cells activated expression of UCP1 and key mitochondrial enzymes of the respiratory chain, and increased cellular mitochondrial DNA content. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The same switch builds more mitochondria to do the burning. organism: Mouse tissue_or_cell_type: Brown fat and skeletal muscle experimental_model: Cloning of PGC-1 from a brown fat cDNA library with ectopic expression in white adipose cells limitations: The founding description of the coactivator. Ectopic expression shows sufficiency in white fat cells; it does not establish the size of the contribution in vivo. exposure: Cold exposure of mice; ectopic PGC-1 expression evidence_span: {"source_cache": "artifacts/cold-research/9529258.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "8986da918d7bde4d0314f51038ee3b1c6413042a1132bb6fbf55ceeb54e79ddf", "start_char": 0, "end_char": 842, "text_sha256": "8986da918d7bde4d0314f51038ee3b1c6413042a1132bb6fbf55ceeb54e79ddf"} [cold-p9529258] A cold-inducible coactivator of nuclear receptors linked to adaptive thermogenesis. (1998). https://pubmed.ncbi.nlm.nih.gov/9529258/ DOI: 10.1016/s0092-8674(00)81410-5
Complete structured claim and evidence
UCP1 expression could be induced by any of the beta-1, beta-2 or beta-3 adrenergic receptor subtypes, but the greatest response came from stimulating all three simultaneously, and beta-3 stimulation did not prevent norepinephrine from further raising adenylyl cyclase activity, suggesting an additive cAMP response.
Human beta-3 adrenergic receptor / ADRB3 → Human mitochondrial uncoupling protein 1 / UCP1 source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/7738011.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "b1c5506f21f40d6674727a5fc3344f2b02f7fc9f2f1e911fd04bfecfc2399175", "start_char": 0, "end_char": 2592, "text_sha256": "b1c5506f21f40d6674727a5fc3344f2b02f7fc9f2f1e911fd04bfecfc2399175"}
experimental_model
Immortalized mouse brown adipocyte cell lines with selective beta-adrenergic agonists and antagonists
exposure
Norepinephrine, the beta-3 selective agonist CL316,243, and subtype-selective antagonists
limitations
A cell-line dissection of receptor subtypes. The additive cAMP response indicates the subtypes are not redundant, but these are immortalized cells.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Mouse cell lines
plain_language
Three different receptors for the same messenger all feed the heat gene, and together they do more than any one alone.
primary_references
[cold-p7738011] Regulation of the uncoupling protein gene (Ucp) by beta 1, beta 2, and beta 3-adrenergic receptor subtypes in immortalized brown adipose cell lines. (1995). https://pubmed.ncbi.nlm.nih.gov/7738011/ DOI: 10.1074/jbc.270.18.10723
tissue_or_cell_type
Brown adipocytes
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 364–375
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Immortalized mouse brown adipocyte cell lines with selective beta-adrenergic agonists and antagonists · source_derived_draft · unverified_draft
### cold-beta-receptors-ucp1 UCP1 expression could be induced by any of the beta-1, beta-2 or beta-3 adrenergic receptor subtypes, but the greatest response came from stimulating all three simultaneously, and beta-3 stimulation did not prevent norepinephrine from further raising adenylyl cyclase activity, suggesting an additive cAMP response. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Three different receptors for the same messenger all feed the heat gene, and together they do more than any one alone. organism: Mouse cell lines tissue_or_cell_type: Brown adipocytes experimental_model: Immortalized mouse brown adipocyte cell lines with selective beta-adrenergic agonists and antagonists limitations: A cell-line dissection of receptor subtypes. The additive cAMP response indicates the subtypes are not redundant, but these are immortalized cells. exposure: Norepinephrine, the beta-3 selective agonist CL316,243, and subtype-selective antagonists evidence_span: {"source_cache": "artifacts/cold-research/7738011.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "b1c5506f21f40d6674727a5fc3344f2b02f7fc9f2f1e911fd04bfecfc2399175", "start_char": 0, "end_char": 2592, "text_sha256": "b1c5506f21f40d6674727a5fc3344f2b02f7fc9f2f1e911fd04bfecfc2399175"} [cold-p7738011] Regulation of the uncoupling protein gene (Ucp) by beta 1, beta 2, and beta 3-adrenergic receptor subtypes in immortalized brown adipose cell lines. (1995). https://pubmed.ncbi.nlm.nih.gov/7738011/ DOI: 10.1074/jbc.270.18.10723
Complete structured claim and evidence
Type 2 iodothyronine deiodinase is a selenoenzyme, the product of the cAMP-dependent Dio2 gene, which increases 10- to 50-fold during cold stress only in brown adipose tissue.
DIO2 → T3 source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/11696583.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "adbd82ff8c43d8a2718cfa752c9a0607c367648d6573b968eb885c883376dc68", "start_char": 0, "end_char": 1332, "text_sha256": "adbd82ff8c43d8a2718cfa752c9a0607c367648d6573b968eb885c883376dc68"}
experimental_model
Mice with targeted disruption of the Dio2 gene, with brown adipocyte assays and T3 rescue
exposure
Cold stress, with norepinephrine, CL316,243 or forskolin stimulation, and a single T3 injection
limitations
The selenoenzyme is the link between thyroid hormone and sympathetic signalling. Plasma T3 was normal in the knockouts, so the defect is local hormone generation, not circulating hormone.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Mouse
plain_language
Cold makes brown fat build a selenium enzyme that manufactures active thyroid hormone on the spot.
primary_references
[cold-p11696583] The type 2 iodothyronine deiodinase is essential for adaptive thermogenesis in brown adipose tissue. (2001). https://pubmed.ncbi.nlm.nih.gov/11696583/ DOI: 10.1172/jci13803
tissue_or_cell_type
Brown adipose tissue
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 377–388
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Mice with targeted disruption of the Dio2 gene, with brown adipocyte assays and T3 rescue · source_derived_draft · unverified_draft
### cold-dio2-selenoenzyme Type 2 iodothyronine deiodinase is a selenoenzyme, the product of the cAMP-dependent Dio2 gene, which increases 10- to 50-fold during cold stress only in brown adipose tissue. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Cold makes brown fat build a selenium enzyme that manufactures active thyroid hormone on the spot. organism: Mouse tissue_or_cell_type: Brown adipose tissue experimental_model: Mice with targeted disruption of the Dio2 gene, with brown adipocyte assays and T3 rescue limitations: The selenoenzyme is the link between thyroid hormone and sympathetic signalling. Plasma T3 was normal in the knockouts, so the defect is local hormone generation, not circulating hormone. exposure: Cold stress, with norepinephrine, CL316,243 or forskolin stimulation, and a single T3 injection evidence_span: {"source_cache": "artifacts/cold-research/11696583.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "adbd82ff8c43d8a2718cfa752c9a0607c367648d6573b968eb885c883376dc68", "start_char": 0, "end_char": 1332, "text_sha256": "adbd82ff8c43d8a2718cfa752c9a0607c367648d6573b968eb885c883376dc68"} [cold-p11696583] The type 2 iodothyronine deiodinase is essential for adaptive thermogenesis in brown adipose tissue. (2001). https://pubmed.ncbi.nlm.nih.gov/11696583/ DOI: 10.1172/jci13803
Complete structured claim and evidence
Cold-exposed Dio2-disrupted mice became hypothermic due to impaired brown adipose thermogenesis despite normal plasma T3 and normal basal UCP1, and survived by compensatory shivering with acute weight loss.
Experimental Dio2-disrupted mouse genotype → Brown adipose tissue thermogenesis source_derived_draftungraded
Experimental context and source evidence
availability_state
nutrient_deficiency Imported condition classification; unverified.
evidence_span
{"source_cache": "artifacts/cold-research/11696583.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "adbd82ff8c43d8a2718cfa752c9a0607c367648d6573b968eb885c883376dc68", "start_char": 0, "end_char": 1332, "text_sha256": "adbd82ff8c43d8a2718cfa752c9a0607c367648d6573b968eb885c883376dc68"}
experimental_model
Mice with targeted disruption of the Dio2 gene, with brown adipocyte assays and T3 rescue
exposure
Cold stress, with norepinephrine, CL316,243 or forskolin stimulation, and a single T3 injection
limitations
The selenoenzyme is the link between thyroid hormone and sympathetic signalling. Plasma T3 was normal in the knockouts, so the defect is local hormone generation, not circulating hormone.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Mouse
plain_language
Normal hormone in the blood was not enough; the tissue had to make its own.
primary_references
[cold-p11696583] The type 2 iodothyronine deiodinase is essential for adaptive thermogenesis in brown adipose tissue. (2001). https://pubmed.ncbi.nlm.nih.gov/11696583/ DOI: 10.1172/jci13803
tissue_or_cell_type
Brown adipose tissue
trigger_kind
nutrient_deficiency Imported condition classification; unverified.
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 390–401
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Mice with targeted disruption of the Dio2 gene, with brown adipocyte assays and T3 rescue · source_derived_draft · unverified_draft
### cold-dio2-null-hypothermia Cold-exposed Dio2-disrupted mice became hypothermic due to impaired brown adipose thermogenesis despite normal plasma T3 and normal basal UCP1, and survived by compensatory shivering with acute weight loss. Condition category: nutrient_deficiency nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Normal hormone in the blood was not enough; the tissue had to make its own. organism: Mouse tissue_or_cell_type: Brown adipose tissue experimental_model: Mice with targeted disruption of the Dio2 gene, with brown adipocyte assays and T3 rescue limitations: The selenoenzyme is the link between thyroid hormone and sympathetic signalling. Plasma T3 was normal in the knockouts, so the defect is local hormone generation, not circulating hormone. exposure: Cold stress, with norepinephrine, CL316,243 or forskolin stimulation, and a single T3 injection evidence_span: {"source_cache": "artifacts/cold-research/11696583.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "adbd82ff8c43d8a2718cfa752c9a0607c367648d6573b968eb885c883376dc68", "start_char": 0, "end_char": 1332, "text_sha256": "adbd82ff8c43d8a2718cfa752c9a0607c367648d6573b968eb885c883376dc68"} [cold-p11696583] The type 2 iodothyronine deiodinase is essential for adaptive thermogenesis in brown adipose tissue. (2001). https://pubmed.ncbi.nlm.nih.gov/11696583/ DOI: 10.1172/jci13803
Complete structured claim and evidence
In Dio2-null brown adipocytes the acute norepinephrine-, CL316,243- or forskolin-induced increases in lipolysis, UCP1 mRNA and oxygen consumption were all reduced because of impaired cAMP generation, and all were completely reversed by a single T3 injection 14 hours earlier.
Experimental Dio2-disrupted mouse genotype → Cyclic adenosine monophosphate source_derived_draftungraded
Experimental context and source evidence
availability_state
nutrient_deficiency Imported condition classification; unverified.
evidence_span
{"source_cache": "artifacts/cold-research/11696583.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "adbd82ff8c43d8a2718cfa752c9a0607c367648d6573b968eb885c883376dc68", "start_char": 0, "end_char": 1332, "text_sha256": "adbd82ff8c43d8a2718cfa752c9a0607c367648d6573b968eb885c883376dc68"}
experimental_model
Mice with targeted disruption of the Dio2 gene, with brown adipocyte assays and T3 rescue
exposure
Cold stress, with norepinephrine, CL316,243 or forskolin stimulation, and a single T3 injection
limitations
The selenoenzyme is the link between thyroid hormone and sympathetic signalling. Plasma T3 was normal in the knockouts, so the defect is local hormone generation, not circulating hormone.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Mouse
plain_language
Without locally made hormone the cell cannot even hear the nerve signal properly.
primary_references
[cold-p11696583] The type 2 iodothyronine deiodinase is essential for adaptive thermogenesis in brown adipose tissue. (2001). https://pubmed.ncbi.nlm.nih.gov/11696583/ DOI: 10.1172/jci13803
tissue_or_cell_type
Brown adipose tissue
trigger_kind
nutrient_deficiency Imported condition classification; unverified.
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 403–414
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Mice with targeted disruption of the Dio2 gene, with brown adipocyte assays and T3 rescue · source_derived_draft · unverified_draft
### cold-dio2-camp-defect In Dio2-null brown adipocytes the acute norepinephrine-, CL316,243- or forskolin-induced increases in lipolysis, UCP1 mRNA and oxygen consumption were all reduced because of impaired cAMP generation, and all were completely reversed by a single T3 injection 14 hours earlier. Condition category: nutrient_deficiency nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Without locally made hormone the cell cannot even hear the nerve signal properly. organism: Mouse tissue_or_cell_type: Brown adipose tissue experimental_model: Mice with targeted disruption of the Dio2 gene, with brown adipocyte assays and T3 rescue limitations: The selenoenzyme is the link between thyroid hormone and sympathetic signalling. Plasma T3 was normal in the knockouts, so the defect is local hormone generation, not circulating hormone. exposure: Cold stress, with norepinephrine, CL316,243 or forskolin stimulation, and a single T3 injection evidence_span: {"source_cache": "artifacts/cold-research/11696583.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "adbd82ff8c43d8a2718cfa752c9a0607c367648d6573b968eb885c883376dc68", "start_char": 0, "end_char": 1332, "text_sha256": "adbd82ff8c43d8a2718cfa752c9a0607c367648d6573b968eb885c883376dc68"} [cold-p11696583] The type 2 iodothyronine deiodinase is essential for adaptive thermogenesis in brown adipose tissue. (2001). https://pubmed.ncbi.nlm.nih.gov/11696583/ DOI: 10.1172/jci13803
Complete structured claim and evidence
The authors propose that intracellularly generated T3 is required to saturate thyroid hormone receptor alpha, which has an approximately fourfold lower T3-binding affinity than receptor beta, making the deiodinase an essential component of the thyroid-sympathetic synergism required for thermal homeostasis.
T3 → Brown adipose tissue thermogenesis source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/11696583.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "adbd82ff8c43d8a2718cfa752c9a0607c367648d6573b968eb885c883376dc68", "start_char": 0, "end_char": 1332, "text_sha256": "adbd82ff8c43d8a2718cfa752c9a0607c367648d6573b968eb885c883376dc68"}
experimental_model
Mice with targeted disruption of the Dio2 gene, with brown adipocyte assays and T3 rescue
exposure
Cold stress, with norepinephrine, CL316,243 or forskolin stimulation, and a single T3 injection
limitations
The selenoenzyme is the link between thyroid hormone and sympathetic signalling. Plasma T3 was normal in the knockouts, so the defect is local hormone generation, not circulating hormone.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Mouse
plain_language
Two receptors need different amounts of hormone, and only local production reaches the hungrier one.
primary_references
[cold-p11696583] The type 2 iodothyronine deiodinase is essential for adaptive thermogenesis in brown adipose tissue. (2001). https://pubmed.ncbi.nlm.nih.gov/11696583/ DOI: 10.1172/jci13803
tissue_or_cell_type
Brown adipose tissue
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 416–427
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Mice with targeted disruption of the Dio2 gene, with brown adipocyte assays and T3 rescue · source_derived_draft · unverified_draft
### cold-dio2-thyroid-sympathetic-synergy The authors propose that intracellularly generated T3 is required to saturate thyroid hormone receptor alpha, which has an approximately fourfold lower T3-binding affinity than receptor beta, making the deiodinase an essential component of the thyroid-sympathetic synergism required for thermal homeostasis. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Two receptors need different amounts of hormone, and only local production reaches the hungrier one. organism: Mouse tissue_or_cell_type: Brown adipose tissue experimental_model: Mice with targeted disruption of the Dio2 gene, with brown adipocyte assays and T3 rescue limitations: The selenoenzyme is the link between thyroid hormone and sympathetic signalling. Plasma T3 was normal in the knockouts, so the defect is local hormone generation, not circulating hormone. exposure: Cold stress, with norepinephrine, CL316,243 or forskolin stimulation, and a single T3 injection evidence_span: {"source_cache": "artifacts/cold-research/11696583.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "adbd82ff8c43d8a2718cfa752c9a0607c367648d6573b968eb885c883376dc68", "start_char": 0, "end_char": 1332, "text_sha256": "adbd82ff8c43d8a2718cfa752c9a0607c367648d6573b968eb885c883376dc68"} [cold-p11696583] The type 2 iodothyronine deiodinase is essential for adaptive thermogenesis in brown adipose tissue. (2001). https://pubmed.ncbi.nlm.nih.gov/11696583/ DOI: 10.1172/jci13803
Complete structured claim and evidence
In brown adipose tissue of hypothyroid rats beta-3 adrenergic receptor number and mRNA increased 4- to 6-fold while both fell in white adipose tissue, T3 injection reverted the changes within 24 hours, and T3 excess caused a greater than 90% reduction of beta-3 receptor mRNA in brown fat but a 5-fold increase in white fat.
T3 → Human beta-3 adrenergic receptor / ADRB3 source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/7628361.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "ee7ba7cfa7ae3387c067f33a03ad9c212801437175f6cb656d5e86b482ed8d64", "start_char": 0, "end_char": 2080, "text_sha256": "ee7ba7cfa7ae3387c067f33a03ad9c212801437175f6cb656d5e86b482ed8d64"}
experimental_model
Brown and white adipose tissue of hypothyroid and T3-treated rats
exposure
Hypothyroidism, T3 replacement and T3 excess
limitations
The reciprocal regulation in the two tissues is the informative part. A post-receptor cAMP defect persisted after receptor numbers were corrected, so receptor count is not the whole story.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Rat
plain_language
Thyroid hormone tunes how loudly each fat depot hears the nerve signal, in opposite directions.
primary_references
[cold-p7628361] Thyroid hormone and norepinephrine signaling in brown adipose tissue. II: Differential effects of thyroid hormone on beta 3-adrenergic receptors in brown and white adipose tissue. (1995). https://pubmed.ncbi.nlm.nih.gov/7628361/ DOI: 10.1210/endo.136.8.7628361
tissue_or_cell_type
Brown and white adipose tissue
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 429–440
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Brown and white adipose tissue of hypothyroid and T3-treated rats · source_derived_draft · unverified_draft
### cold-thyroid-beta3-regulation In brown adipose tissue of hypothyroid rats beta-3 adrenergic receptor number and mRNA increased 4- to 6-fold while both fell in white adipose tissue, T3 injection reverted the changes within 24 hours, and T3 excess caused a greater than 90% reduction of beta-3 receptor mRNA in brown fat but a 5-fold increase in white fat. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Thyroid hormone tunes how loudly each fat depot hears the nerve signal, in opposite directions. organism: Rat tissue_or_cell_type: Brown and white adipose tissue experimental_model: Brown and white adipose tissue of hypothyroid and T3-treated rats limitations: The reciprocal regulation in the two tissues is the informative part. A post-receptor cAMP defect persisted after receptor numbers were corrected, so receptor count is not the whole story. exposure: Hypothyroidism, T3 replacement and T3 excess evidence_span: {"source_cache": "artifacts/cold-research/7628361.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "ee7ba7cfa7ae3387c067f33a03ad9c212801437175f6cb656d5e86b482ed8d64", "start_char": 0, "end_char": 2080, "text_sha256": "ee7ba7cfa7ae3387c067f33a03ad9c212801437175f6cb656d5e86b482ed8d64"} [cold-p7628361] Thyroid hormone and norepinephrine signaling in brown adipose tissue. II: Differential effects of thyroid hormone on beta 3-adrenergic receptors in brown and white adipose tissue. (1995). https://pubmed.ncbi.nlm.nih.gov/7628361/ DOI: 10.1210/endo.136.8.7628361
Complete structured claim and evidence
Creatine enhanced respiration in beige-fat mitochondria when ADP was limiting, and cold exposure stimulated mitochondrial creatine kinase activity and induced coordinated expression of creatine metabolism genes in murine beige fat.
Creatine → The futile creatine substrate cycle in thermogenic adipocytes source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/26496606.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "f2d52dfe935e633b9d69280d707a124080d6f6c4d650f94bc8cf6a00f26e43e7", "start_char": 0, "end_char": 1097, "text_sha256": "f2d52dfe935e633b9d69280d707a124080d6f6c4d650f94bc8cf6a00f26e43e7"}
experimental_model
Quantitative mitochondrial proteomics of brown and beige fat with pharmacological creatine reduction
exposure
Cold exposure, beta-3 agonist administration, and creatine depletion
limitations
Identifies a UCP1-independent route. Pharmacological creatine reduction is a blunt tool, and the compensatory induction in UCP1-deficient mice is an expression finding.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Mouse
plain_language
A second heat route runs a creatine cycle that burns energy on purpose.
primary_references
[cold-p26496606] A creatine-driven substrate cycle enhances energy expenditure and thermogenesis in beige fat. (2015). https://pubmed.ncbi.nlm.nih.gov/26496606/ DOI: 10.1016/j.cell.2015.09.035
tissue_or_cell_type
Beige and brown adipose tissue
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 442–453
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Quantitative mitochondrial proteomics of brown and beige fat with pharmacological creatine reduction · source_derived_draft · unverified_draft
### cold-creatine-cycle Creatine enhanced respiration in beige-fat mitochondria when ADP was limiting, and cold exposure stimulated mitochondrial creatine kinase activity and induced coordinated expression of creatine metabolism genes in murine beige fat. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: A second heat route runs a creatine cycle that burns energy on purpose. organism: Mouse tissue_or_cell_type: Beige and brown adipose tissue experimental_model: Quantitative mitochondrial proteomics of brown and beige fat with pharmacological creatine reduction limitations: Identifies a UCP1-independent route. Pharmacological creatine reduction is a blunt tool, and the compensatory induction in UCP1-deficient mice is an expression finding. exposure: Cold exposure, beta-3 agonist administration, and creatine depletion evidence_span: {"source_cache": "artifacts/cold-research/26496606.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "f2d52dfe935e633b9d69280d707a124080d6f6c4d650f94bc8cf6a00f26e43e7", "start_char": 0, "end_char": 1097, "text_sha256": "f2d52dfe935e633b9d69280d707a124080d6f6c4d650f94bc8cf6a00f26e43e7"} [cold-p26496606] A creatine-driven substrate cycle enhances energy expenditure and thermogenesis in beige fat. (2015). https://pubmed.ncbi.nlm.nih.gov/26496606/ DOI: 10.1016/j.cell.2015.09.035
Complete structured claim and evidence
Pharmacological reduction of creatine decreased whole-body energy expenditure after beta-3 agonist administration and reduced beige and brown adipose metabolic rate, and creatine metabolism genes were compensatorily induced when UCP1-dependent thermogenesis was ablated, with creatine reduction in Ucp1-deficient mice lowering core body temperature.
Pharmacological reduction of tissue creatine levels → Whole-body energy expenditure source_derived_draftungraded
Experimental context and source evidence
availability_state
machinery_impairment Imported condition classification; unverified.
evidence_span
{"source_cache": "artifacts/cold-research/26496606.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "f2d52dfe935e633b9d69280d707a124080d6f6c4d650f94bc8cf6a00f26e43e7", "start_char": 0, "end_char": 1097, "text_sha256": "f2d52dfe935e633b9d69280d707a124080d6f6c4d650f94bc8cf6a00f26e43e7"}
experimental_model
Quantitative mitochondrial proteomics of brown and beige fat with pharmacological creatine reduction
exposure
Cold exposure, beta-3 agonist administration, and creatine depletion
limitations
Identifies a UCP1-independent route. Pharmacological creatine reduction is a blunt tool, and the compensatory induction in UCP1-deficient mice is an expression finding.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Mouse
plain_language
Take creatine away and the burn falls, most visibly when the usual heat protein is already gone.
primary_references
[cold-p26496606] A creatine-driven substrate cycle enhances energy expenditure and thermogenesis in beige fat. (2015). https://pubmed.ncbi.nlm.nih.gov/26496606/ DOI: 10.1016/j.cell.2015.09.035
tissue_or_cell_type
Beige and brown adipose tissue
trigger_kind
machinery_impairment Imported condition classification; unverified.
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 455–466
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Quantitative mitochondrial proteomics of brown and beige fat with pharmacological creatine reduction · source_derived_draft · unverified_draft
### cold-creatine-depletion-energy Pharmacological reduction of creatine decreased whole-body energy expenditure after beta-3 agonist administration and reduced beige and brown adipose metabolic rate, and creatine metabolism genes were compensatorily induced when UCP1-dependent thermogenesis was ablated, with creatine reduction in Ucp1-deficient mice lowering core body temperature. Condition category: machinery_impairment nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Take creatine away and the burn falls, most visibly when the usual heat protein is already gone. organism: Mouse tissue_or_cell_type: Beige and brown adipose tissue experimental_model: Quantitative mitochondrial proteomics of brown and beige fat with pharmacological creatine reduction limitations: Identifies a UCP1-independent route. Pharmacological creatine reduction is a blunt tool, and the compensatory induction in UCP1-deficient mice is an expression finding. exposure: Cold exposure, beta-3 agonist administration, and creatine depletion evidence_span: {"source_cache": "artifacts/cold-research/26496606.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "f2d52dfe935e633b9d69280d707a124080d6f6c4d650f94bc8cf6a00f26e43e7", "start_char": 0, "end_char": 1097, "text_sha256": "f2d52dfe935e633b9d69280d707a124080d6f6c4d650f94bc8cf6a00f26e43e7"} [cold-p26496606] A creatine-driven substrate cycle enhances energy expenditure and thermogenesis in beige fat. (2015). https://pubmed.ncbi.nlm.nih.gov/26496606/ DOI: 10.1016/j.cell.2015.09.035
Complete structured claim and evidence
Mice lacking the first and rate-limiting enzyme of creatine biosynthesis selectively in fat were prone to diet-induced obesity through suppression of the elevated energy expenditure normally seen with high-calorie feeding, with a blunted capacity for beta-3 adrenergic activation of metabolic rate that was rescued by dietary creatine supplementation.
Adipocyte-selective Gatm knockout mouse genotype → Diet-induced thermogenesis source_derived_draftungraded
Experimental context and source evidence
availability_state
machinery_impairment Imported condition classification; unverified.
evidence_span
{"source_cache": "artifacts/cold-research/28844881.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "1341345f147cd7e59119d062b0523a4bf6087a6936b3434bb76a305033a724eb", "start_char": 0, "end_char": 1069, "text_sha256": "1341345f147cd7e59119d062b0523a4bf6087a6936b3434bb76a305033a724eb"}
experimental_model
Adipocyte-selective knockout of glycine amidinotransferase in mice
exposure
High-calorie feeding, beta-3 adrenergic activation, and dietary creatine supplementation
limitations
A genetic test of the same cycle with a dietary rescue. It concerns diet-induced thermogenesis rather than cold thermogenesis directly.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Mouse
plain_language
Blocking the cell from making creatine caused obesity, and feeding creatine fixed it.
primary_references
[cold-p28844881] Genetic Depletion of Adipocyte Creatine Metabolism Inhibits Diet-Induced Thermogenesis and Drives Obesity. (2017). https://pubmed.ncbi.nlm.nih.gov/28844881/ DOI: 10.1016/j.cmet.2017.08.009
tissue_or_cell_type
Adipose tissue
trigger_kind
machinery_impairment Imported condition classification; unverified.
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 468–479
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Adipocyte-selective knockout of glycine amidinotransferase in mice · source_derived_draft · unverified_draft
### cold-gatm-knockout-obesity Mice lacking the first and rate-limiting enzyme of creatine biosynthesis selectively in fat were prone to diet-induced obesity through suppression of the elevated energy expenditure normally seen with high-calorie feeding, with a blunted capacity for beta-3 adrenergic activation of metabolic rate that was rescued by dietary creatine supplementation. Condition category: machinery_impairment nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Blocking the cell from making creatine caused obesity, and feeding creatine fixed it. organism: Mouse tissue_or_cell_type: Adipose tissue experimental_model: Adipocyte-selective knockout of glycine amidinotransferase in mice limitations: A genetic test of the same cycle with a dietary rescue. It concerns diet-induced thermogenesis rather than cold thermogenesis directly. exposure: High-calorie feeding, beta-3 adrenergic activation, and dietary creatine supplementation evidence_span: {"source_cache": "artifacts/cold-research/28844881.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "1341345f147cd7e59119d062b0523a4bf6087a6936b3434bb76a305033a724eb", "start_char": 0, "end_char": 1069, "text_sha256": "1341345f147cd7e59119d062b0523a4bf6087a6936b3434bb76a305033a724eb"} [cold-p28844881] Genetic Depletion of Adipocyte Creatine Metabolism Inhibits Diet-Induced Thermogenesis and Drives Obesity. (2017). https://pubmed.ncbi.nlm.nih.gov/28844881/ DOI: 10.1016/j.cmet.2017.08.009
Complete structured claim and evidence
Cold exposure increased circulating irisin and FGF21, with irisin secretion induced in proportion to shivering intensity and of similar magnitude to exercise-stimulated secretion.
Shivering thermogenesis → Circulating irisin concentration source_derived_draftungraded
Experimental context and source evidence
evidence_span
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experimental_model
Human cold exposure with circulating myokine measurement and human adipocyte treatment
exposure
Cold exposure sufficient to induce shivering; FNDC5 and FGF21 treatment of human adipocytes
limitations
The proportionality to shivering intensity is the mechanistic link. Depot-specific adipocyte responses mean this is not a uniform browning effect.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Shivering muscle releases the same messenger exercising muscle does, in proportion to how hard it shivers.
primary_references
[cold-p24506871] Irisin and FGF21 are cold-induced endocrine activators of brown fat function in humans. (2014). https://pubmed.ncbi.nlm.nih.gov/24506871/ DOI: 10.1016/j.cmet.2013.12.017
tissue_or_cell_type
Skeletal muscle and adipose tissue
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 481–492
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human cold exposure with circulating myokine measurement and human adipocyte treatment · source_derived_draft · unverified_draft
### cold-irisin-shivering Cold exposure increased circulating irisin and FGF21, with irisin secretion induced in proportion to shivering intensity and of similar magnitude to exercise-stimulated secretion. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Shivering muscle releases the same messenger exercising muscle does, in proportion to how hard it shivers. organism: Human tissue_or_cell_type: Skeletal muscle and adipose tissue experimental_model: Human cold exposure with circulating myokine measurement and human adipocyte treatment limitations: The proportionality to shivering intensity is the mechanistic link. Depot-specific adipocyte responses mean this is not a uniform browning effect. exposure: Cold exposure sufficient to induce shivering; FNDC5 and FGF21 treatment of human adipocytes evidence_span: {"source_cache": "artifacts/cold-research/24506871.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "980c2630ed13bf2a55f813a6df483edb68a1d6370c0f1afdfcbc7df7817eb610", "start_char": 0, "end_char": 1149, "text_sha256": "980c2630ed13bf2a55f813a6df483edb68a1d6370c0f1afdfcbc7df7817eb610"} [cold-p24506871] Irisin and FGF21 are cold-induced endocrine activators of brown fat function in humans. (2014). https://pubmed.ncbi.nlm.nih.gov/24506871/ DOI: 10.1016/j.cmet.2013.12.017
Complete structured claim and evidence
FNDC5 and FGF21 treatment upregulated human adipocyte brown-fat gene and protein expression and thermogenesis in a depot-specific manner, suggesting a thermogenic cold-activated endocrine axis between muscle and fat.
Irisin → Browning of human adipocytes: brown-fat gene and protein expression source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/24506871.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "980c2630ed13bf2a55f813a6df483edb68a1d6370c0f1afdfcbc7df7817eb610", "start_char": 0, "end_char": 1149, "text_sha256": "980c2630ed13bf2a55f813a6df483edb68a1d6370c0f1afdfcbc7df7817eb610"}
experimental_model
Human cold exposure with circulating myokine measurement and human adipocyte treatment
exposure
Cold exposure sufficient to induce shivering; FNDC5 and FGF21 treatment of human adipocytes
limitations
The proportionality to shivering intensity is the mechanistic link. Depot-specific adipocyte responses mean this is not a uniform browning effect.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
The messenger from shivering muscle tells fat to start making heat.
primary_references
[cold-p24506871] Irisin and FGF21 are cold-induced endocrine activators of brown fat function in humans. (2014). https://pubmed.ncbi.nlm.nih.gov/24506871/ DOI: 10.1016/j.cmet.2013.12.017
tissue_or_cell_type
Skeletal muscle and adipose tissue
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 494–505
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human cold exposure with circulating myokine measurement and human adipocyte treatment · source_derived_draft · unverified_draft
### cold-irisin-browning FNDC5 and FGF21 treatment upregulated human adipocyte brown-fat gene and protein expression and thermogenesis in a depot-specific manner, suggesting a thermogenic cold-activated endocrine axis between muscle and fat. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The messenger from shivering muscle tells fat to start making heat. organism: Human tissue_or_cell_type: Skeletal muscle and adipose tissue experimental_model: Human cold exposure with circulating myokine measurement and human adipocyte treatment limitations: The proportionality to shivering intensity is the mechanistic link. Depot-specific adipocyte responses mean this is not a uniform browning effect. exposure: Cold exposure sufficient to induce shivering; FNDC5 and FGF21 treatment of human adipocytes evidence_span: {"source_cache": "artifacts/cold-research/24506871.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "980c2630ed13bf2a55f813a6df483edb68a1d6370c0f1afdfcbc7df7817eb610", "start_char": 0, "end_char": 1149, "text_sha256": "980c2630ed13bf2a55f813a6df483edb68a1d6370c0f1afdfcbc7df7817eb610"} [cold-p24506871] Irisin and FGF21 are cold-induced endocrine activators of brown fat function in humans. (2014). https://pubmed.ncbi.nlm.nih.gov/24506871/ DOI: 10.1016/j.cmet.2013.12.017
Complete structured claim and evidence
Brown adipose volume correlated with the change in metabolic heat production during the mild cold phase, and positively correlated with rectal temperature at the end of that phase, which in turn correlated with shivering onset time.
Detectable brown adipose tissue volume → Non-shivering thermogenesis source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/32948898.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "699fc07665c5f8800951348b6948dba539ed6aed5d1d354d4793be8f9f731b6a", "start_char": 0, "end_char": 1697, "text_sha256": "699fc07665c5f8800951348b6948dba539ed6aed5d1d354d4793be8f9f731b6a"}
experimental_model
Eighteen men with measured brown adipose volume during gradual cold exposure
exposure
Gradual cooling to 18.6 degrees C for non-shivering thermogenesis and 11.6 degrees C for shivering onset
limitations
Correlational human physiology. It tests whether muscle compensates for low brown fat, and finds an earlier shivering onset instead.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
People with more of the tissue made more heat without shivering and started shivering later.
primary_references
[cold-p32948898] Multiorgan contribution to non-shivering and shivering thermogenesis and vascular responses during gradual cold exposure in humans. (2020). https://pubmed.ncbi.nlm.nih.gov/32948898/ DOI: 10.1007/s00421-020-04496-1
tissue_or_cell_type
Brown adipose tissue and skeletal muscle
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 507–518
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Eighteen men with measured brown adipose volume during gradual cold exposure · source_derived_draft · unverified_draft
### cold-bat-volume-nst Brown adipose volume correlated with the change in metabolic heat production during the mild cold phase, and positively correlated with rectal temperature at the end of that phase, which in turn correlated with shivering onset time. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: People with more of the tissue made more heat without shivering and started shivering later. organism: Human tissue_or_cell_type: Brown adipose tissue and skeletal muscle experimental_model: Eighteen men with measured brown adipose volume during gradual cold exposure limitations: Correlational human physiology. It tests whether muscle compensates for low brown fat, and finds an earlier shivering onset instead. exposure: Gradual cooling to 18.6 degrees C for non-shivering thermogenesis and 11.6 degrees C for shivering onset evidence_span: {"source_cache": "artifacts/cold-research/32948898.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "699fc07665c5f8800951348b6948dba539ed6aed5d1d354d4793be8f9f731b6a", "start_char": 0, "end_char": 1697, "text_sha256": "699fc07665c5f8800951348b6948dba539ed6aed5d1d354d4793be8f9f731b6a"} [cold-p32948898] Multiorgan contribution to non-shivering and shivering thermogenesis and vascular responses during gradual cold exposure in humans. (2020). https://pubmed.ncbi.nlm.nih.gov/32948898/ DOI: 10.1007/s00421-020-04496-1
Complete structured claim and evidence
Skeletal muscle mass correlated with baseline metabolic heat production but not with non-shivering thermogenesis, and skin blood flow and skin temperatures did not correlate with non-shivering thermogenesis or brown adipose volume.
Skeletal muscle as a thermogenic and postural organ → Non-shivering thermogenesis source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/32948898.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "699fc07665c5f8800951348b6948dba539ed6aed5d1d354d4793be8f9f731b6a", "start_char": 0, "end_char": 1697, "text_sha256": "699fc07665c5f8800951348b6948dba539ed6aed5d1d354d4793be8f9f731b6a"}
experimental_model
Eighteen men with measured brown adipose volume during gradual cold exposure
exposure
Gradual cooling to 18.6 degrees C for non-shivering thermogenesis and 11.6 degrees C for shivering onset
limitations
Correlational human physiology. It tests whether muscle compensates for low brown fat, and finds an earlier shivering onset instead.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Muscle does not quietly take over the job; it just starts shivering sooner.
primary_references
[cold-p32948898] Multiorgan contribution to non-shivering and shivering thermogenesis and vascular responses during gradual cold exposure in humans. (2020). https://pubmed.ncbi.nlm.nih.gov/32948898/ DOI: 10.1007/s00421-020-04496-1
tissue_or_cell_type
Brown adipose tissue and skeletal muscle
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 520–531
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Eighteen men with measured brown adipose volume during gradual cold exposure · source_derived_draft · unverified_draft
### cold-muscle-does-not-compensate Skeletal muscle mass correlated with baseline metabolic heat production but not with non-shivering thermogenesis, and skin blood flow and skin temperatures did not correlate with non-shivering thermogenesis or brown adipose volume. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Muscle does not quietly take over the job; it just starts shivering sooner. organism: Human tissue_or_cell_type: Brown adipose tissue and skeletal muscle experimental_model: Eighteen men with measured brown adipose volume during gradual cold exposure limitations: Correlational human physiology. It tests whether muscle compensates for low brown fat, and finds an earlier shivering onset instead. exposure: Gradual cooling to 18.6 degrees C for non-shivering thermogenesis and 11.6 degrees C for shivering onset evidence_span: {"source_cache": "artifacts/cold-research/32948898.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "699fc07665c5f8800951348b6948dba539ed6aed5d1d354d4793be8f9f731b6a", "start_char": 0, "end_char": 1697, "text_sha256": "699fc07665c5f8800951348b6948dba539ed6aed5d1d354d4793be8f9f731b6a"} [cold-p32948898] Multiorgan contribution to non-shivering and shivering thermogenesis and vascular responses during gradual cold exposure in humans. (2020). https://pubmed.ncbi.nlm.nih.gov/32948898/ DOI: 10.1007/s00421-020-04496-1
Complete structured claim and evidence
Tyrosine hydroxylase is a non-heme iron enzyme that uses molecular oxygen to hydroxylate tyrosine to L-DOPA and tetrahydrobiopterin to 4a-hydroxybiopterin in the rate-limiting step of the catecholamine biosynthetic pathway.
Iron → Human tyrosine hydroxylase source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/9753429.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "3c76ec6d5dadb463c0a044175d5a78fbd02df4da7c339029c8c232e8878175b9", "start_char": 0, "end_char": 1695, "text_sha256": "3c76ec6d5dadb463c0a044175d5a78fbd02df4da7c339029c8c232e8878175b9"}
experimental_model
Crystal structure of rat tyrosine hydroxylase with a cofactor analogue and iron at 2.3 angstrom
exposure
Bound 7,8-dihydrobiopterin and iron
limitations
Structural chemistry of the rate-limiting step. It is a rat enzyme structure with a cofactor analogue, not a measurement of iron status in an animal.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Rat enzyme
plain_language
The first and slowest step of making noradrenaline needs an iron atom and a molecule of oxygen.
primary_references
[cold-p9753429] Crystal structure of tyrosine hydroxylase with bound cofactor analogue and iron at 2.3 A resolution: self-hydroxylation of Phe300 and the pterin-binding site. (1998). https://pubmed.ncbi.nlm.nih.gov/9753429/ DOI: 10.1021/bi981462g
tissue_or_cell_type
Purified catalytic and tetramerization domains
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 533–544
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Crystal structure of rat tyrosine hydroxylase with a cofactor analogue and iron at 2.3 angstrom · source_derived_draft · unverified_draft
### cold-th-iron-oxygen-pterin Tyrosine hydroxylase is a non-heme iron enzyme that uses molecular oxygen to hydroxylate tyrosine to L-DOPA and tetrahydrobiopterin to 4a-hydroxybiopterin in the rate-limiting step of the catecholamine biosynthetic pathway. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The first and slowest step of making noradrenaline needs an iron atom and a molecule of oxygen. organism: Rat enzyme tissue_or_cell_type: Purified catalytic and tetramerization domains experimental_model: Crystal structure of rat tyrosine hydroxylase with a cofactor analogue and iron at 2.3 angstrom limitations: Structural chemistry of the rate-limiting step. It is a rat enzyme structure with a cofactor analogue, not a measurement of iron status in an animal. exposure: Bound 7,8-dihydrobiopterin and iron evidence_span: {"source_cache": "artifacts/cold-research/9753429.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "3c76ec6d5dadb463c0a044175d5a78fbd02df4da7c339029c8c232e8878175b9", "start_char": 0, "end_char": 1695, "text_sha256": "3c76ec6d5dadb463c0a044175d5a78fbd02df4da7c339029c8c232e8878175b9"} [cold-p9753429] Crystal structure of tyrosine hydroxylase with bound cofactor analogue and iron at 2.3 A resolution: self-hydroxylation of Phe300 and the pterin-binding site. (1998). https://pubmed.ncbi.nlm.nih.gov/9753429/ DOI: 10.1021/bi981462g
Complete structured claim and evidence
The pterin binds in the active-site cleft forming an aromatic stacking interaction with Phe300, which is itself hydroxylated in the meta position by an autocatalytic process and anchored by a hydrogen bond to the carbonyl of Gln310; the iron sits 5.6 angstrom from the pterin 4a carbon, and molecular oxygen could bind in a bridging position between the pterin and the iron before substrate hydroxylation.
Tetrahydrobiopterin / BH4 → Human tyrosine hydroxylase source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/9753429.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "3c76ec6d5dadb463c0a044175d5a78fbd02df4da7c339029c8c232e8878175b9", "start_char": 0, "end_char": 1695, "text_sha256": "3c76ec6d5dadb463c0a044175d5a78fbd02df4da7c339029c8c232e8878175b9"}
experimental_model
Crystal structure of rat tyrosine hydroxylase with a cofactor analogue and iron at 2.3 angstrom
exposure
Bound 7,8-dihydrobiopterin and iron
limitations
Structural chemistry of the rate-limiting step. It is a rat enzyme structure with a cofactor analogue, not a measurement of iron status in an animal.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Rat enzyme
plain_language
The oxygen molecule slots into the gap between the cofactor and the iron.
primary_references
[cold-p9753429] Crystal structure of tyrosine hydroxylase with bound cofactor analogue and iron at 2.3 A resolution: self-hydroxylation of Phe300 and the pterin-binding site. (1998). https://pubmed.ncbi.nlm.nih.gov/9753429/ DOI: 10.1021/bi981462g
tissue_or_cell_type
Purified catalytic and tetramerization domains
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 546–557
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Crystal structure of rat tyrosine hydroxylase with a cofactor analogue and iron at 2.3 angstrom · source_derived_draft · unverified_draft
### cold-th-pterin-geometry The pterin binds in the active-site cleft forming an aromatic stacking interaction with Phe300, which is itself hydroxylated in the meta position by an autocatalytic process and anchored by a hydrogen bond to the carbonyl of Gln310; the iron sits 5.6 angstrom from the pterin 4a carbon, and molecular oxygen could bind in a bridging position between the pterin and the iron before substrate hydroxylation. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The oxygen molecule slots into the gap between the cofactor and the iron. organism: Rat enzyme tissue_or_cell_type: Purified catalytic and tetramerization domains experimental_model: Crystal structure of rat tyrosine hydroxylase with a cofactor analogue and iron at 2.3 angstrom limitations: Structural chemistry of the rate-limiting step. It is a rat enzyme structure with a cofactor analogue, not a measurement of iron status in an animal. exposure: Bound 7,8-dihydrobiopterin and iron evidence_span: {"source_cache": "artifacts/cold-research/9753429.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "3c76ec6d5dadb463c0a044175d5a78fbd02df4da7c339029c8c232e8878175b9", "start_char": 0, "end_char": 1695, "text_sha256": "3c76ec6d5dadb463c0a044175d5a78fbd02df4da7c339029c8c232e8878175b9"} [cold-p9753429] Crystal structure of tyrosine hydroxylase with bound cofactor analogue and iron at 2.3 A resolution: self-hydroxylation of Phe300 and the pterin-binding site. (1998). https://pubmed.ncbi.nlm.nih.gov/9753429/ DOI: 10.1021/bi981462g
Complete structured claim and evidence
Dopamine beta-hydroxylase specifically binds 8 moles of copper per mole of tetramer, confirmed by radiolabel, atomic absorption, NMR and EPR titration, and catalytic rate increased with copper up to that ratio and was constant thereafter, so this stoichiometry is required for maximal activity.
Copper → Dopamine beta-hydroxylase catalytic turnover source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/6323422.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "dac85ce0ad7c7d5994b97d55b129050a0e7ca8bf96943578d272054db6a07a62", "start_char": 0, "end_char": 1346, "text_sha256": "dac85ce0ad7c7d5994b97d55b129050a0e7ca8bf96943578d272054db6a07a62"}
experimental_model
Copper titration of bovine adrenal dopamine beta-hydroxylase followed by NMR, EPR and inhibitor kinetics
exposure
Titration with copper and measurement of catalytic rate
limitations
Stoichiometry measured three independent ways. It establishes how much copper the enzyme needs, not how much copper a person needs.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Bovine enzyme
plain_language
The enzyme that turns dopamine into noradrenaline needs exactly eight copper atoms to work fully.
primary_references
[cold-p6323422] Kinetic and spectroscopic studies of the interaction of copper with dopamine beta-hydroxylase. (1984). https://pubmed.ncbi.nlm.nih.gov/6323422/ DOI: 10.1016/s0021-9258(17)43105-x
tissue_or_cell_type
Adrenal medulla enzyme
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 559–570
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Copper titration of bovine adrenal dopamine beta-hydroxylase followed by NMR, EPR and inhibitor kinetics · source_derived_draft · unverified_draft
### cold-dbh-copper-stoichiometry Dopamine beta-hydroxylase specifically binds 8 moles of copper per mole of tetramer, confirmed by radiolabel, atomic absorption, NMR and EPR titration, and catalytic rate increased with copper up to that ratio and was constant thereafter, so this stoichiometry is required for maximal activity. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The enzyme that turns dopamine into noradrenaline needs exactly eight copper atoms to work fully. organism: Bovine enzyme tissue_or_cell_type: Adrenal medulla enzyme experimental_model: Copper titration of bovine adrenal dopamine beta-hydroxylase followed by NMR, EPR and inhibitor kinetics limitations: Stoichiometry measured three independent ways. It establishes how much copper the enzyme needs, not how much copper a person needs. exposure: Titration with copper and measurement of catalytic rate evidence_span: {"source_cache": "artifacts/cold-research/6323422.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "dac85ce0ad7c7d5994b97d55b129050a0e7ca8bf96943578d272054db6a07a62", "start_char": 0, "end_char": 1346, "text_sha256": "dac85ce0ad7c7d5994b97d55b129050a0e7ca8bf96943578d272054db6a07a62"} [cold-p6323422] Kinetic and spectroscopic studies of the interaction of copper with dopamine beta-hydroxylase. (1984). https://pubmed.ncbi.nlm.nih.gov/6323422/ DOI: 10.1016/s0021-9258(17)43105-x
Complete structured claim and evidence
Below a ratio of eight copper atoms per tetramer, the measured rate of enzymatic catalysis rose in proportion to the copper present rather than being maximal.
Dopamine beta-hydroxylase below its eight-copper stoichiometry → Dopamine beta-hydroxylase catalytic turnover source_derived_draftungraded
Experimental context and source evidence
availability_state
nutrient_deficiency Imported condition classification; unverified.
evidence_span
{"source_cache": "artifacts/cold-research/6323422.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "dac85ce0ad7c7d5994b97d55b129050a0e7ca8bf96943578d272054db6a07a62", "start_char": 0, "end_char": 1346, "text_sha256": "dac85ce0ad7c7d5994b97d55b129050a0e7ca8bf96943578d272054db6a07a62"}
experimental_model
Copper titration of bovine adrenal dopamine beta-hydroxylase followed by NMR, EPR and inhibitor kinetics
exposure
Titration with copper and measurement of catalytic rate
limitations
Stoichiometry measured three independent ways. It establishes how much copper the enzyme needs, not how much copper a person needs.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Bovine enzyme
plain_language
Short the enzyme of copper and it runs proportionally slower.
primary_references
[cold-p6323422] Kinetic and spectroscopic studies of the interaction of copper with dopamine beta-hydroxylase. (1984). https://pubmed.ncbi.nlm.nih.gov/6323422/ DOI: 10.1016/s0021-9258(17)43105-x
tissue_or_cell_type
Adrenal medulla enzyme
trigger_kind
nutrient_deficiency Imported condition classification; unverified.
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 572–583
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Copper titration of bovine adrenal dopamine beta-hydroxylase followed by NMR, EPR and inhibitor kinetics · source_derived_draft · unverified_draft
### cold-copper-free-dbh-activity Below a ratio of eight copper atoms per tetramer, the measured rate of enzymatic catalysis rose in proportion to the copper present rather than being maximal. Condition category: nutrient_deficiency nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Short the enzyme of copper and it runs proportionally slower. organism: Bovine enzyme tissue_or_cell_type: Adrenal medulla enzyme experimental_model: Copper titration of bovine adrenal dopamine beta-hydroxylase followed by NMR, EPR and inhibitor kinetics limitations: Stoichiometry measured three independent ways. It establishes how much copper the enzyme needs, not how much copper a person needs. exposure: Titration with copper and measurement of catalytic rate evidence_span: {"source_cache": "artifacts/cold-research/6323422.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "dac85ce0ad7c7d5994b97d55b129050a0e7ca8bf96943578d272054db6a07a62", "start_char": 0, "end_char": 1346, "text_sha256": "dac85ce0ad7c7d5994b97d55b129050a0e7ca8bf96943578d272054db6a07a62"} [cold-p6323422] Kinetic and spectroscopic studies of the interaction of copper with dopamine beta-hydroxylase. (1984). https://pubmed.ncbi.nlm.nih.gov/6323422/ DOI: 10.1016/s0021-9258(17)43105-x
Complete structured claim and evidence
Ascorbate is the presumed in vivo reductant of dopamine beta-monooxygenase; the one-electron reductant ferrocyanide was nearly as kinetically competent, while dopamine as sole reductant reduced enzymic copper in a rate-limiting step 40-fold slower than with ascorbate, and the reductant binds at a site physically distinct from the substrate site.
L-Ascorbate → Dopamine beta-hydroxylase catalytic turnover source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/3676254.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "e929132eed0f1c94ab0bdbef6e31bca7ecbed222cf9b585e17a1cfae7e93c82a", "start_char": 0, "end_char": 1648, "text_sha256": "e929132eed0f1c94ab0bdbef6e31bca7ecbed222cf9b585e17a1cfae7e93c82a"}
experimental_model
Steady-state kinetics of dopamine beta-monooxygenase with structurally distinct reductants
exposure
Ascorbate, ferrocyanide or dopamine itself as the reducing agent, with deuterium isotope effects
limitations
A kinetic comparison identifying ascorbate as the presumed physiological reductant and locating a separate binding site for it. Truncated abstract; the reductant site is inferred from kinetics and modelling.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Bovine enzyme
plain_language
Vitamin C is what hands the enzyme back its electrons, and without it the reaction crawls.
primary_references
[cold-p3676254] Characterization of alternate reductant binding and electron transfer in the dopamine beta-monooxygenase reaction. (1987). https://pubmed.ncbi.nlm.nih.gov/3676254/ DOI: 10.1021/bi00391a013
tissue_or_cell_type
Purified enzyme
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 585–596
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Steady-state kinetics of dopamine beta-monooxygenase with structurally distinct reductants · source_derived_draft · unverified_draft
### cold-ascorbate-reductant Ascorbate is the presumed in vivo reductant of dopamine beta-monooxygenase; the one-electron reductant ferrocyanide was nearly as kinetically competent, while dopamine as sole reductant reduced enzymic copper in a rate-limiting step 40-fold slower than with ascorbate, and the reductant binds at a site physically distinct from the substrate site. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Vitamin C is what hands the enzyme back its electrons, and without it the reaction crawls. organism: Bovine enzyme tissue_or_cell_type: Purified enzyme experimental_model: Steady-state kinetics of dopamine beta-monooxygenase with structurally distinct reductants limitations: A kinetic comparison identifying ascorbate as the presumed physiological reductant and locating a separate binding site for it. Truncated abstract; the reductant site is inferred from kinetics and modelling. exposure: Ascorbate, ferrocyanide or dopamine itself as the reducing agent, with deuterium isotope effects evidence_span: {"source_cache": "artifacts/cold-research/3676254.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "e929132eed0f1c94ab0bdbef6e31bca7ecbed222cf9b585e17a1cfae7e93c82a", "start_char": 0, "end_char": 1648, "text_sha256": "e929132eed0f1c94ab0bdbef6e31bca7ecbed222cf9b585e17a1cfae7e93c82a"} [cold-p3676254] Characterization of alternate reductant binding and electron transfer in the dopamine beta-monooxygenase reaction. (1987). https://pubmed.ncbi.nlm.nih.gov/3676254/ DOI: 10.1021/bi00391a013
Complete structured claim and evidence
Chromaffin granules must shuttle reducing equivalents inward to re-reduce ascorbate oxidised during noradrenaline synthesis: tyramine-driven turnover oxidised intragranular ascorbate with a stoichiometry of octopamine synthesised to ascorbate oxidised near unity, 95% inhibited by the enzyme inhibitor disulfiram, and abolished or reversed by extragranular ascorbate, while labelled ascorbate showed no transmembrane transport of the vitamin itself.
Cytosolic ascorbate pool → Reduced ascorbate inside the chromaffin granule source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/3949732.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "9db1233389aeb375adfd655ea04f39ccb05e22773f367aaa1292bb21698242e1", "start_char": 0, "end_char": 2000, "text_sha256": "9db1233389aeb375adfd655ea04f39ccb05e22773f367aaa1292bb21698242e1"}
experimental_model
Intact bovine chromaffin granules undergoing dopamine beta-hydroxylase turnover with labelled ascorbate
exposure
Tyramine- or dopamine-stimulated turnover with extragranular ascorbate
limitations
An in vitro demonstration in intact granules. Ascorbate itself does not cross the membrane, which is precisely why a shuttle is required.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Bovine
plain_language
The vitamin cannot cross into the vesicle, so the cell passes electrons across the membrane instead.
primary_references
[cold-p3949732] Evidence for an ascorbate shuttle for the transfer of reducing equivalents across chromaffin granule membranes. (1986). https://pubmed.ncbi.nlm.nih.gov/3949732/ DOI: 10.1016/s0021-9258(17)35819-2
tissue_or_cell_type
Adrenal chromaffin granules
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 598–609
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Intact bovine chromaffin granules undergoing dopamine beta-hydroxylase turnover with labelled ascorbate · source_derived_draft · unverified_draft
### cold-ascorbate-shuttle Chromaffin granules must shuttle reducing equivalents inward to re-reduce ascorbate oxidised during noradrenaline synthesis: tyramine-driven turnover oxidised intragranular ascorbate with a stoichiometry of octopamine synthesised to ascorbate oxidised near unity, 95% inhibited by the enzyme inhibitor disulfiram, and abolished or reversed by extragranular ascorbate, while labelled ascorbate showed no transmembrane transport of the vitamin itself. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The vitamin cannot cross into the vesicle, so the cell passes electrons across the membrane instead. organism: Bovine tissue_or_cell_type: Adrenal chromaffin granules experimental_model: Intact bovine chromaffin granules undergoing dopamine beta-hydroxylase turnover with labelled ascorbate limitations: An in vitro demonstration in intact granules. Ascorbate itself does not cross the membrane, which is precisely why a shuttle is required. exposure: Tyramine- or dopamine-stimulated turnover with extragranular ascorbate evidence_span: {"source_cache": "artifacts/cold-research/3949732.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "9db1233389aeb375adfd655ea04f39ccb05e22773f367aaa1292bb21698242e1", "start_char": 0, "end_char": 2000, "text_sha256": "9db1233389aeb375adfd655ea04f39ccb05e22773f367aaa1292bb21698242e1"} [cold-p3949732] Evidence for an ascorbate shuttle for the transfer of reducing equivalents across chromaffin granule membranes. (1986). https://pubmed.ncbi.nlm.nih.gov/3949732/ DOI: 10.1016/s0021-9258(17)35819-2
Complete structured claim and evidence
Incubation with tyramine produced a time-dependent decrease in reduced intragranular ascorbate proportional to extragranular tyramine concentration over 50 microM to 2 mM.
Dopamine beta-hydroxylase catalytic turnover → Reduced ascorbate inside the chromaffin granule source_derived_draftungraded
Experimental context and source evidence
availability_state
nutrient_deficiency Imported condition classification; unverified.
evidence_span
{"source_cache": "artifacts/cold-research/3949732.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "9db1233389aeb375adfd655ea04f39ccb05e22773f367aaa1292bb21698242e1", "start_char": 0, "end_char": 2000, "text_sha256": "9db1233389aeb375adfd655ea04f39ccb05e22773f367aaa1292bb21698242e1"}
experimental_model
Intact bovine chromaffin granules undergoing dopamine beta-hydroxylase turnover with labelled ascorbate
exposure
Tyramine- or dopamine-stimulated turnover with extragranular ascorbate
limitations
An in vitro demonstration in intact granules. Ascorbate itself does not cross the membrane, which is precisely why a shuttle is required.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Bovine
plain_language
Every molecule of noradrenaline made costs the vesicle a molecule of vitamin C.
primary_references
[cold-p3949732] Evidence for an ascorbate shuttle for the transfer of reducing equivalents across chromaffin granule membranes. (1986). https://pubmed.ncbi.nlm.nih.gov/3949732/ DOI: 10.1016/s0021-9258(17)35819-2
tissue_or_cell_type
Adrenal chromaffin granules
trigger_kind
nutrient_deficiency Imported condition classification; unverified.
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 611–622
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Intact bovine chromaffin granules undergoing dopamine beta-hydroxylase turnover with labelled ascorbate · source_derived_draft · unverified_draft
### cold-ascorbate-depletion-in-granule Incubation with tyramine produced a time-dependent decrease in reduced intragranular ascorbate proportional to extragranular tyramine concentration over 50 microM to 2 mM. Condition category: nutrient_deficiency nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Every molecule of noradrenaline made costs the vesicle a molecule of vitamin C. organism: Bovine tissue_or_cell_type: Adrenal chromaffin granules experimental_model: Intact bovine chromaffin granules undergoing dopamine beta-hydroxylase turnover with labelled ascorbate limitations: An in vitro demonstration in intact granules. Ascorbate itself does not cross the membrane, which is precisely why a shuttle is required. exposure: Tyramine- or dopamine-stimulated turnover with extragranular ascorbate evidence_span: {"source_cache": "artifacts/cold-research/3949732.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "9db1233389aeb375adfd655ea04f39ccb05e22773f367aaa1292bb21698242e1", "start_char": 0, "end_char": 2000, "text_sha256": "9db1233389aeb375adfd655ea04f39ccb05e22773f367aaa1292bb21698242e1"} [cold-p3949732] Evidence for an ascorbate shuttle for the transfer of reducing equivalents across chromaffin granule membranes. (1986). https://pubmed.ncbi.nlm.nih.gov/3949732/ DOI: 10.1016/s0021-9258(17)35819-2
Complete structured claim and evidence
Heat produced by the thermogenic action of adrenaline may represent more than a quarter of total cold thermogenesis, and in winter swimmers shivering was induced later during cooling, after 40 minutes, suggesting an important contribution of non-shivering thermogenesis to the early thermogenic response.
Epinephrine → Catecholamine-driven cold thermogenesis source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/10825419.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "df5b07f571e51ae21572ac56aa97d1a9dffcd44fe8f5ead4c929086cbbd37e62", "start_char": 0, "end_char": 2308, "text_sha256": "df5b07f571e51ae21572ac56aa97d1a9dffcd44fe8f5ead4c929086cbbd37e62"}
experimental_model
Cold-adapted winter swimmers and controls during one hour of immersion at 13 degrees C
exposure
One hour of cold water immersion at 13 degrees C
limitations
A comparison of adapted and unadapted people. The adrenaline contribution to thermogenesis is the authors’ estimate from their thermoregulation data, not a direct measurement of a hormone-driven heat fraction.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
A quarter of the heat may come from a hormone rather than from muscle shaking.
primary_references
[cold-p10825419] Thermoregulation in winter swimmers and physiological significance of human catecholamine thermogenesis. (2000). https://pubmed.ncbi.nlm.nih.gov/10825419/ DOI: 10.1111/j.1469-445x.2000.01909.x
tissue_or_cell_type
Whole body thermoregulation
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 624–635
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Cold-adapted winter swimmers and controls during one hour of immersion at 13 degrees C · source_derived_draft · unverified_draft
### cold-catecholamine-thermogenesis-share Heat produced by the thermogenic action of adrenaline may represent more than a quarter of total cold thermogenesis, and in winter swimmers shivering was induced later during cooling, after 40 minutes, suggesting an important contribution of non-shivering thermogenesis to the early thermogenic response. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: A quarter of the heat may come from a hormone rather than from muscle shaking. organism: Human tissue_or_cell_type: Whole body thermoregulation experimental_model: Cold-adapted winter swimmers and controls during one hour of immersion at 13 degrees C limitations: A comparison of adapted and unadapted people. The adrenaline contribution to thermogenesis is the authors’ estimate from their thermoregulation data, not a direct measurement of a hormone-driven heat fraction. exposure: One hour of cold water immersion at 13 degrees C evidence_span: {"source_cache": "artifacts/cold-research/10825419.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "df5b07f571e51ae21572ac56aa97d1a9dffcd44fe8f5ead4c929086cbbd37e62", "start_char": 0, "end_char": 2308, "text_sha256": "df5b07f571e51ae21572ac56aa97d1a9dffcd44fe8f5ead4c929086cbbd37e62"} [cold-p10825419] Thermoregulation in winter swimmers and physiological significance of human catecholamine thermogenesis. (2000). https://pubmed.ncbi.nlm.nih.gov/10825419/ DOI: 10.1111/j.1469-445x.2000.01909.x
Complete structured claim and evidence
In winter swimmers the thermoregulatory threshold for inducing cold thermogenesis was lowered by 0.34 degrees C while apparent hypothalamic thermosensitivity was unchanged, and the magnitude of cold thermogenesis related solely to rectal temperature, indicating predominance of central temperature input.
Cold water immersion → Thermoregulatory threshold for inducing cold thermogenesis source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/10825419.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "df5b07f571e51ae21572ac56aa97d1a9dffcd44fe8f5ead4c929086cbbd37e62", "start_char": 0, "end_char": 2308, "text_sha256": "df5b07f571e51ae21572ac56aa97d1a9dffcd44fe8f5ead4c929086cbbd37e62"}
experimental_model
Cold-adapted winter swimmers and controls during one hour of immersion at 13 degrees C
exposure
One hour of cold water immersion at 13 degrees C
limitations
A comparison of adapted and unadapted people. The adrenaline contribution to thermogenesis is the authors’ estimate from their thermoregulation data, not a direct measurement of a hormone-driven heat fraction.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Repeated exposure moves the set point at which the body decides to make heat.
primary_references
[cold-p10825419] Thermoregulation in winter swimmers and physiological significance of human catecholamine thermogenesis. (2000). https://pubmed.ncbi.nlm.nih.gov/10825419/ DOI: 10.1111/j.1469-445x.2000.01909.x
tissue_or_cell_type
Whole body thermoregulation
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 637–648
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Cold-adapted winter swimmers and controls during one hour of immersion at 13 degrees C · source_derived_draft · unverified_draft
### cold-winter-swimmer-threshold In winter swimmers the thermoregulatory threshold for inducing cold thermogenesis was lowered by 0.34 degrees C while apparent hypothalamic thermosensitivity was unchanged, and the magnitude of cold thermogenesis related solely to rectal temperature, indicating predominance of central temperature input. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Repeated exposure moves the set point at which the body decides to make heat. organism: Human tissue_or_cell_type: Whole body thermoregulation experimental_model: Cold-adapted winter swimmers and controls during one hour of immersion at 13 degrees C limitations: A comparison of adapted and unadapted people. The adrenaline contribution to thermogenesis is the authors’ estimate from their thermoregulation data, not a direct measurement of a hormone-driven heat fraction. exposure: One hour of cold water immersion at 13 degrees C evidence_span: {"source_cache": "artifacts/cold-research/10825419.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "df5b07f571e51ae21572ac56aa97d1a9dffcd44fe8f5ead4c929086cbbd37e62", "start_char": 0, "end_char": 2308, "text_sha256": "df5b07f571e51ae21572ac56aa97d1a9dffcd44fe8f5ead4c929086cbbd37e62"} [cold-p10825419] Thermoregulation in winter swimmers and physiological significance of human catecholamine thermogenesis. (2000). https://pubmed.ncbi.nlm.nih.gov/10825419/ DOI: 10.1111/j.1469-445x.2000.01909.x
Complete structured claim and evidence
Winter swimmers showed bradycardia and a greater reduction in plasma volume during cooling, indirectly indicating restriction of heat loss, with only a non-significant increase in subcutaneous fat, and exhibited metabolic, hypothermic and insulative types of cold adaptation together.
Cold water immersion → Plasma volume source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/10825419.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "df5b07f571e51ae21572ac56aa97d1a9dffcd44fe8f5ead4c929086cbbd37e62", "start_char": 0, "end_char": 2308, "text_sha256": "df5b07f571e51ae21572ac56aa97d1a9dffcd44fe8f5ead4c929086cbbd37e62"}
experimental_model
Cold-adapted winter swimmers and controls during one hour of immersion at 13 degrees C
exposure
One hour of cold water immersion at 13 degrees C
limitations
A comparison of adapted and unadapted people. The adrenaline contribution to thermogenesis is the authors’ estimate from their thermoregulation data, not a direct measurement of a hormone-driven heat fraction.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Adapted swimmers hold heat in as well as making more of it, without getting fatter.
primary_references
[cold-p10825419] Thermoregulation in winter swimmers and physiological significance of human catecholamine thermogenesis. (2000). https://pubmed.ncbi.nlm.nih.gov/10825419/ DOI: 10.1111/j.1469-445x.2000.01909.x
tissue_or_cell_type
Whole body thermoregulation
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 650–661
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Cold-adapted winter swimmers and controls during one hour of immersion at 13 degrees C · source_derived_draft · unverified_draft
### cold-winter-swimmer-insulation Winter swimmers showed bradycardia and a greater reduction in plasma volume during cooling, indirectly indicating restriction of heat loss, with only a non-significant increase in subcutaneous fat, and exhibited metabolic, hypothermic and insulative types of cold adaptation together. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Adapted swimmers hold heat in as well as making more of it, without getting fatter. organism: Human tissue_or_cell_type: Whole body thermoregulation experimental_model: Cold-adapted winter swimmers and controls during one hour of immersion at 13 degrees C limitations: A comparison of adapted and unadapted people. The adrenaline contribution to thermogenesis is the authors’ estimate from their thermoregulation data, not a direct measurement of a hormone-driven heat fraction. exposure: One hour of cold water immersion at 13 degrees C evidence_span: {"source_cache": "artifacts/cold-research/10825419.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "df5b07f571e51ae21572ac56aa97d1a9dffcd44fe8f5ead4c929086cbbd37e62", "start_char": 0, "end_char": 2308, "text_sha256": "df5b07f571e51ae21572ac56aa97d1a9dffcd44fe8f5ead4c929086cbbd37e62"} [cold-p10825419] Thermoregulation in winter swimmers and physiological significance of human catecholamine thermogenesis. (2000). https://pubmed.ncbi.nlm.nih.gov/10825419/ DOI: 10.1111/j.1469-445x.2000.01909.x
Complete structured claim and evidence
Mean plasma noradrenaline fell significantly from autumn to spring and more so in winter swimmers, but with no statistically significant difference between swimmers and controls; systolic blood pressure fell in swimmers, and plasma homovanillic acid and beta-endorphin were unchanged across all seasonal samples in both groups.
Cold water immersion → Plasma noradrenaline concentration source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/12546194.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "08c39cf0438d2f97c989e86721085415de696a3c7df99f5c2dc6529c40f7aeb2", "start_char": 0, "end_char": 1785, "text_sha256": "08c39cf0438d2f97c989e86721085415de696a3c7df99f5c2dc6529c40f7aeb2"}
experimental_model
Follow-up of winter swimmers and non-swimmer controls sampled in autumn, winter and spring
exposure
One winter swimming season
limitations
A seasonal follow-up with a control group. Its negative conclusion is explicit: the changes seen in swimmers also occurred in controls.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Across a whole season the swimmers changed no more than the people who stayed dry.
primary_references
[cold-p12546194] Plasma catecholamines, serotonin and their metabolites and beta-endorphin of winter swimmers during one winter. Possible correlations to psychological traits. (2002). https://pubmed.ncbi.nlm.nih.gov/12546194/ DOI: 10.3402/ijch.v61i4.17494
tissue_or_cell_type
Plasma hormones and blood pressure
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 663–674
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Follow-up of winter swimmers and non-swimmer controls sampled in autumn, winter and spring · source_derived_draft · unverified_draft
### cold-seasonal-catecholamine-fall Mean plasma noradrenaline fell significantly from autumn to spring and more so in winter swimmers, but with no statistically significant difference between swimmers and controls; systolic blood pressure fell in swimmers, and plasma homovanillic acid and beta-endorphin were unchanged across all seasonal samples in both groups. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Across a whole season the swimmers changed no more than the people who stayed dry. organism: Human tissue_or_cell_type: Plasma hormones and blood pressure experimental_model: Follow-up of winter swimmers and non-swimmer controls sampled in autumn, winter and spring limitations: A seasonal follow-up with a control group. Its negative conclusion is explicit: the changes seen in swimmers also occurred in controls. exposure: One winter swimming season evidence_span: {"source_cache": "artifacts/cold-research/12546194.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "08c39cf0438d2f97c989e86721085415de696a3c7df99f5c2dc6529c40f7aeb2", "start_char": 0, "end_char": 1785, "text_sha256": "08c39cf0438d2f97c989e86721085415de696a3c7df99f5c2dc6529c40f7aeb2"} [cold-p12546194] Plasma catecholamines, serotonin and their metabolites and beta-endorphin of winter swimmers during one winter. Possible correlations to psychological traits. (2002). https://pubmed.ncbi.nlm.nih.gov/12546194/ DOI: 10.3402/ijch.v61i4.17494
Complete structured claim and evidence
Repeated cold air exposure increased the oral metabolic clearance rate of T3 by 5.4 l/day/m2 and the disposal rate by 10.2 nmol/day/m2, and these increases were not dependent on thyrotropin or thyroxine, since they were unchanged in men given replacement T3 whose TSH and T4 fell by about half.
T3 → Metabolic clearance rate of triiodothyronine source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/1636702.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "4e0d8127d3ebb682588afd84b635d2607dce9ebec4e7573d25e7baae58fc9301", "start_char": 0, "end_char": 1183, "text_sha256": "4e0d8127d3ebb682588afd84b635d2607dce9ebec4e7573d25e7baae58fc9301"}
experimental_model
Sixteen men given oral T3 before, during and after 80 cold air exposures, with and without T3 replacement
exposure
Eighty exposures to 4 degrees C air, ten per week
limitations
Cold air rather than water immersion, recorded because it isolates the thyroid hormone kinetics. The pharmacological oral T3 dose is not physiological.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Cold makes the body consume active thyroid hormone faster, independently of the usual feedback loop.
primary_references
[cold-p1636702] Multiple cold air exposures change oral triiodothyronine kinetics in normal men. (1992). https://pubmed.ncbi.nlm.nih.gov/1636702/ DOI: 10.1152/ajpendo.1992.263.1.e85
tissue_or_cell_type
Whole body thyroid hormone kinetics
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 676–687
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Sixteen men given oral T3 before, during and after 80 cold air exposures, with and without T3 replacement · source_derived_draft · unverified_draft
### cold-cold-t3-clearance Repeated cold air exposure increased the oral metabolic clearance rate of T3 by 5.4 l/day/m2 and the disposal rate by 10.2 nmol/day/m2, and these increases were not dependent on thyrotropin or thyroxine, since they were unchanged in men given replacement T3 whose TSH and T4 fell by about half. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Cold makes the body consume active thyroid hormone faster, independently of the usual feedback loop. organism: Human tissue_or_cell_type: Whole body thyroid hormone kinetics experimental_model: Sixteen men given oral T3 before, during and after 80 cold air exposures, with and without T3 replacement limitations: Cold air rather than water immersion, recorded because it isolates the thyroid hormone kinetics. The pharmacological oral T3 dose is not physiological. exposure: Eighty exposures to 4 degrees C air, ten per week evidence_span: {"source_cache": "artifacts/cold-research/1636702.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "4e0d8127d3ebb682588afd84b635d2607dce9ebec4e7573d25e7baae58fc9301", "start_char": 0, "end_char": 1183, "text_sha256": "4e0d8127d3ebb682588afd84b635d2607dce9ebec4e7573d25e7baae58fc9301"} [cold-p1636702] Multiple cold air exposures change oral triiodothyronine kinetics in normal men. (1992). https://pubmed.ncbi.nlm.nih.gov/1636702/ DOI: 10.1152/ajpendo.1992.263.1.e85
Complete structured claim and evidence
Baseline reduced glutathione concentration and erythrocyte superoxide dismutase and catalase activities were higher in winter swimmers than in controls, which the authors interpret as an adaptive response to repeated oxidative stress and postulate as a mechanism of increased tolerance to environmental stress.
Cold water immersion → Adaptation to repeated oxidative stress source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/10396606.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "fdd2deec82fad8f9e148848c443d5b173ec42c0e07d9045c59773f7109883a7b", "start_char": 0, "end_char": 1139, "text_sha256": "fdd2deec82fad8f9e148848c443d5b173ec42c0e07d9045c59773f7109883a7b"}
experimental_model
Winter swimmers compared with people who had never taken part, sampled for erythrocyte and plasma antioxidants
exposure
Habitual ice bathing
limitations
A cross-sectional comparison, so self-selection cannot be excluded. The authors frame it as adaptation to repeated oxidative stress.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
People who swim in ice water carry more antioxidant defence at rest.
primary_references
[cold-p10396606] Improved antioxidative protection in winter swimmers. (1999). https://pubmed.ncbi.nlm.nih.gov/10396606/ DOI: 10.1093/qjmed/92.4.193
tissue_or_cell_type
Erythrocytes and plasma
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 689–700
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Winter swimmers compared with people who had never taken part, sampled for erythrocyte and plasma antioxidants · source_derived_draft · unverified_draft
### cold-winter-swimmer-antioxidants Baseline reduced glutathione concentration and erythrocyte superoxide dismutase and catalase activities were higher in winter swimmers than in controls, which the authors interpret as an adaptive response to repeated oxidative stress and postulate as a mechanism of increased tolerance to environmental stress. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: People who swim in ice water carry more antioxidant defence at rest. organism: Human tissue_or_cell_type: Erythrocytes and plasma experimental_model: Winter swimmers compared with people who had never taken part, sampled for erythrocyte and plasma antioxidants limitations: A cross-sectional comparison, so self-selection cannot be excluded. The authors frame it as adaptation to repeated oxidative stress. exposure: Habitual ice bathing evidence_span: {"source_cache": "artifacts/cold-research/10396606.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "fdd2deec82fad8f9e148848c443d5b173ec42c0e07d9045c59773f7109883a7b", "start_char": 0, "end_char": 1139, "text_sha256": "fdd2deec82fad8f9e148848c443d5b173ec42c0e07d9045c59773f7109883a7b"} [cold-p10396606] Improved antioxidative protection in winter swimmers. (1999). https://pubmed.ncbi.nlm.nih.gov/10396606/ DOI: 10.1093/qjmed/92.4.193
Complete structured claim and evidence
The effect of a single cold water immersion at 14 degrees C for 1 hour on the immune system, monitored immediately after immersion, was minimal.
Cold water immersion → Proportion of circulating monocytes source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/8925815.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "ca491f2f549a1e245e952978c0df82c4075622affdf114a70315c0cce8583ff4", "start_char": 0, "end_char": 1732, "text_sha256": "ca491f2f549a1e245e952978c0df82c4075622affdf114a70315c0cce8583ff4"}
experimental_model
Athletic young men given a single immersion and then repeated immersions over six weeks
exposure
14 degrees C for 1 hour, three times a week for six weeks
limitations
The authors themselves state the biological significance of the changes remains to be elucidated. Most immune measures did not change.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
One cold plunge does essentially nothing measurable to the immune system.
primary_references
[cold-p8925815] Immune system of cold-exposed and cold-adapted humans. (1996). https://pubmed.ncbi.nlm.nih.gov/8925815/ DOI: 10.1007/bf00242274
tissue_or_cell_type
Immune system
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 702–713
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Athletic young men given a single immersion and then repeated immersions over six weeks · source_derived_draft · unverified_draft
### cold-single-immersion-immune The effect of a single cold water immersion at 14 degrees C for 1 hour on the immune system, monitored immediately after immersion, was minimal. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: One cold plunge does essentially nothing measurable to the immune system. organism: Human tissue_or_cell_type: Immune system experimental_model: Athletic young men given a single immersion and then repeated immersions over six weeks limitations: The authors themselves state the biological significance of the changes remains to be elucidated. Most immune measures did not change. exposure: 14 degrees C for 1 hour, three times a week for six weeks evidence_span: {"source_cache": "artifacts/cold-research/8925815.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "ca491f2f549a1e245e952978c0df82c4075622affdf114a70315c0cce8583ff4", "start_char": 0, "end_char": 1732, "text_sha256": "ca491f2f549a1e245e952978c0df82c4075622affdf114a70315c0cce8583ff4"} [cold-p8925815] Immune system of cold-exposed and cold-adapted humans. (1996). https://pubmed.ncbi.nlm.nih.gov/8925815/ DOI: 10.1007/bf00242274
Complete structured claim and evidence
With immersions continued three times a week for six weeks, a small but significant increase appeared in the proportions of monocytes and of lymphocytes expressing the IL-2 receptor CD25, and in plasma tumour necrosis factor alpha, with increases in haptoglobin and haemopexin, while interleukin-1 beta, C-reactive protein, immunoglobulins, complement and total leucocyte counts showed no significant change.
Cold water immersion → Lymphocytes expressing the IL-2 receptor CD25 source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/8925815.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "ca491f2f549a1e245e952978c0df82c4075622affdf114a70315c0cce8583ff4", "start_char": 0, "end_char": 1732, "text_sha256": "ca491f2f549a1e245e952978c0df82c4075622affdf114a70315c0cce8583ff4"}
experimental_model
Athletic young men given a single immersion and then repeated immersions over six weeks
exposure
14 degrees C for 1 hour, three times a week for six weeks
limitations
The authors themselves state the biological significance of the changes remains to be elucidated. Most immune measures did not change.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Six weeks of repetition nudges a few immune markers, and leaves most untouched.
primary_references
[cold-p8925815] Immune system of cold-exposed and cold-adapted humans. (1996). https://pubmed.ncbi.nlm.nih.gov/8925815/ DOI: 10.1007/bf00242274
tissue_or_cell_type
Immune system
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 715–726
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Athletic young men given a single immersion and then repeated immersions over six weeks · source_derived_draft · unverified_draft
### cold-repeated-immersion-immune With immersions continued three times a week for six weeks, a small but significant increase appeared in the proportions of monocytes and of lymphocytes expressing the IL-2 receptor CD25, and in plasma tumour necrosis factor alpha, with increases in haptoglobin and haemopexin, while interleukin-1 beta, C-reactive protein, immunoglobulins, complement and total leucocyte counts showed no significant change. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Six weeks of repetition nudges a few immune markers, and leaves most untouched. organism: Human tissue_or_cell_type: Immune system experimental_model: Athletic young men given a single immersion and then repeated immersions over six weeks limitations: The authors themselves state the biological significance of the changes remains to be elucidated. Most immune measures did not change. exposure: 14 degrees C for 1 hour, three times a week for six weeks evidence_span: {"source_cache": "artifacts/cold-research/8925815.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "ca491f2f549a1e245e952978c0df82c4075622affdf114a70315c0cce8583ff4", "start_char": 0, "end_char": 1732, "text_sha256": "ca491f2f549a1e245e952978c0df82c4075622affdf114a70315c0cce8583ff4"} [cold-p8925815] Immune system of cold-exposed and cold-adapted humans. (1996). https://pubmed.ncbi.nlm.nih.gov/8925815/ DOI: 10.1007/bf00242274
Complete structured claim and evidence
Tension, fatigue, memory and negative mood scores in swimmers decreased significantly with the duration of the swimming period, and after four months swimmers reported significantly greater vigour and activity than controls, with those who had rheumatism, fibromyalgia or asthma reporting relief of pain.
Cold water immersion → Profile of mood state disturbance: tension, fatigue and negative mood source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/15253480.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "ca9c92e52fcba46785e37751a7b714fcb6ca5a915d12b621e87bc811223a9bfa", "start_char": 0, "end_char": 983, "text_sha256": "ca9c92e52fcba46785e37751a7b714fcb6ca5a915d12b621e87bc811223a9bfa"}
experimental_model
Winter swimmers and controls completing mood questionnaires before and after a four-month season
exposure
Regular winter swimming over four months
limitations
A questionnaire study without randomisation or blinding, in people who chose to swim. The pain reports are uncontrolled self-report.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Over a season the swimmers felt less tense and tired and more energetic than the people who did not swim.
primary_references
[cold-p15253480] Winter swimming improves general well-being. (2004). https://pubmed.ncbi.nlm.nih.gov/15253480/ DOI: 10.3402/ijch.v63i2.17700
tissue_or_cell_type
Mood and subjective symptoms
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 728–739
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Winter swimmers and controls completing mood questionnaires before and after a four-month season · source_derived_draft · unverified_draft
### cold-winter-swimming-mood Tension, fatigue, memory and negative mood scores in swimmers decreased significantly with the duration of the swimming period, and after four months swimmers reported significantly greater vigour and activity than controls, with those who had rheumatism, fibromyalgia or asthma reporting relief of pain. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Over a season the swimmers felt less tense and tired and more energetic than the people who did not swim. organism: Human tissue_or_cell_type: Mood and subjective symptoms experimental_model: Winter swimmers and controls completing mood questionnaires before and after a four-month season limitations: A questionnaire study without randomisation or blinding, in people who chose to swim. The pain reports are uncontrolled self-report. exposure: Regular winter swimming over four months evidence_span: {"source_cache": "artifacts/cold-research/15253480.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "ca9c92e52fcba46785e37751a7b714fcb6ca5a915d12b621e87bc811223a9bfa", "start_char": 0, "end_char": 983, "text_sha256": "ca9c92e52fcba46785e37751a7b714fcb6ca5a915d12b621e87bc811223a9bfa"} [cold-p15253480] Winter swimming improves general well-being. (2004). https://pubmed.ncbi.nlm.nih.gov/15253480/ DOI: 10.3402/ijch.v63i2.17700
Complete structured claim and evidence
Negative affect was lower 180 minutes after a single 15-minute immersion at 10 degrees C while positive affect did not change, and cortisol was lower at 180 minutes, whereas serum beta-endorphins did not change throughout the trial.
Cold water immersion → Self-reported negative affect source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/37866096.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "2180ef37d9e3dda6b7785769dcc2e4deb89b07a12ffed469e52c80af563cff54", "start_char": 0, "end_char": 1665, "text_sha256": "2180ef37d9e3dda6b7785769dcc2e4deb89b07a12ffed469e52c80af563cff54"}
experimental_model
Sixteen healthy adults completing one 15-minute immersion at 10 degrees C with Doppler ultrasound and blood sampling
exposure
One 15-minute immersion at 10 degrees C
limitations
A small single-bout study. Beta-endorphin did not change, which bears on the common attribution of the mood effect to endorphins.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Three hours after one plunge people felt less bad, though not better, and the endorphin explanation did not hold up.
primary_references
[cold-p37866096] Cardiovascular and mood responses to an acute bout of cold water immersion. (2023). https://pubmed.ncbi.nlm.nih.gov/37866096/ DOI: 10.1016/j.jtherbio.2023.103727
tissue_or_cell_type
Brachial artery and mood
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 741–752
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Sixteen healthy adults completing one 15-minute immersion at 10 degrees C with Doppler ultrasound and blood sampling · source_derived_draft · unverified_draft
### cold-acute-negative-affect Negative affect was lower 180 minutes after a single 15-minute immersion at 10 degrees C while positive affect did not change, and cortisol was lower at 180 minutes, whereas serum beta-endorphins did not change throughout the trial. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Three hours after one plunge people felt less bad, though not better, and the endorphin explanation did not hold up. organism: Human tissue_or_cell_type: Brachial artery and mood experimental_model: Sixteen healthy adults completing one 15-minute immersion at 10 degrees C with Doppler ultrasound and blood sampling limitations: A small single-bout study. Beta-endorphin did not change, which bears on the common attribution of the mood effect to endorphins. exposure: One 15-minute immersion at 10 degrees C evidence_span: {"source_cache": "artifacts/cold-research/37866096.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "2180ef37d9e3dda6b7785769dcc2e4deb89b07a12ffed469e52c80af563cff54", "start_char": 0, "end_char": 1665, "text_sha256": "2180ef37d9e3dda6b7785769dcc2e4deb89b07a12ffed469e52c80af563cff54"} [cold-p37866096] Cardiovascular and mood responses to an acute bout of cold water immersion. (2023). https://pubmed.ncbi.nlm.nih.gov/37866096/ DOI: 10.1016/j.jtherbio.2023.103727
Complete structured claim and evidence
Forearm vascular conductance was reduced at 15 minutes of immersion and 30 minutes after, and total and antegrade shear stress and the oscillatory shear index were reduced 30 minutes after immersion, with no difference in retrograde shear.
Cold water immersion → Forearm vascular conductance source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/37866096.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "2180ef37d9e3dda6b7785769dcc2e4deb89b07a12ffed469e52c80af563cff54", "start_char": 0, "end_char": 1665, "text_sha256": "2180ef37d9e3dda6b7785769dcc2e4deb89b07a12ffed469e52c80af563cff54"}
experimental_model
Sixteen healthy adults completing one 15-minute immersion at 10 degrees C with Doppler ultrasound and blood sampling
exposure
One 15-minute immersion at 10 degrees C
limitations
A small single-bout study. Beta-endorphin did not change, which bears on the common attribution of the mood effect to endorphins.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
The vessels in the arm stayed narrowed for at least half an hour afterwards.
primary_references
[cold-p37866096] Cardiovascular and mood responses to an acute bout of cold water immersion. (2023). https://pubmed.ncbi.nlm.nih.gov/37866096/ DOI: 10.1016/j.jtherbio.2023.103727
tissue_or_cell_type
Brachial artery and mood
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 754–765
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Sixteen healthy adults completing one 15-minute immersion at 10 degrees C with Doppler ultrasound and blood sampling · source_derived_draft · unverified_draft
### cold-acute-shear-stress Forearm vascular conductance was reduced at 15 minutes of immersion and 30 minutes after, and total and antegrade shear stress and the oscillatory shear index were reduced 30 minutes after immersion, with no difference in retrograde shear. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The vessels in the arm stayed narrowed for at least half an hour afterwards. organism: Human tissue_or_cell_type: Brachial artery and mood experimental_model: Sixteen healthy adults completing one 15-minute immersion at 10 degrees C with Doppler ultrasound and blood sampling limitations: A small single-bout study. Beta-endorphin did not change, which bears on the common attribution of the mood effect to endorphins. exposure: One 15-minute immersion at 10 degrees C evidence_span: {"source_cache": "artifacts/cold-research/37866096.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "2180ef37d9e3dda6b7785769dcc2e4deb89b07a12ffed469e52c80af563cff54", "start_char": 0, "end_char": 1665, "text_sha256": "2180ef37d9e3dda6b7785769dcc2e4deb89b07a12ffed469e52c80af563cff54"} [cold-p37866096] Cardiovascular and mood responses to an acute bout of cold water immersion. (2023). https://pubmed.ncbi.nlm.nih.gov/37866096/ DOI: 10.1016/j.jtherbio.2023.103727
Complete structured claim and evidence
Five minutes of immersion at 15 degrees C after training reduced the usual exercise-induced decrease in parasympathetic activity, with vagal-related heart rate variability likely to very likely improved on days 2 to 5 compared with control.
Cold water immersion → Vagal-related heart rate variability (Ln rMSSD) source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/21941017.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "0cd5dfad3441e660d67198cf010e5fa160936cb66c37b129b575d29d74940910", "start_char": 0, "end_char": 1567, "text_sha256": "0cd5dfad3441e660d67198cf010e5fa160936cb66c37b129b575d29d74940910"}
experimental_model
Eight highly trained swimmers over two matched training weeks in randomised order
exposure
5 minutes of seated recovery at 15 degrees C after the last training session each day
limitations
A small crossover in elite athletes using magnitude-based inference. Sleep quality is self-reported.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
A short cold dip after training keeps the calming branch of the nervous system from dropping.
primary_references
[cold-p21941017] Effect of daily cold water immersion on heart rate variability and subjective ratings of well-being in highly trained swimmers. (2012). https://pubmed.ncbi.nlm.nih.gov/21941017/ DOI: 10.1123/ijspp.7.1.33
tissue_or_cell_type
Autonomic nervous system and sleep
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 767–778
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Eight highly trained swimmers over two matched training weeks in randomised order · source_derived_draft · unverified_draft
### cold-hrv-recovery Five minutes of immersion at 15 degrees C after training reduced the usual exercise-induced decrease in parasympathetic activity, with vagal-related heart rate variability likely to very likely improved on days 2 to 5 compared with control. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: A short cold dip after training keeps the calming branch of the nervous system from dropping. organism: Human tissue_or_cell_type: Autonomic nervous system and sleep experimental_model: Eight highly trained swimmers over two matched training weeks in randomised order limitations: A small crossover in elite athletes using magnitude-based inference. Sleep quality is self-reported. exposure: 5 minutes of seated recovery at 15 degrees C after the last training session each day evidence_span: {"source_cache": "artifacts/cold-research/21941017.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "0cd5dfad3441e660d67198cf010e5fa160936cb66c37b129b575d29d74940910", "start_char": 0, "end_char": 1567, "text_sha256": "0cd5dfad3441e660d67198cf010e5fa160936cb66c37b129b575d29d74940910"} [cold-p21941017] Effect of daily cold water immersion on heart rate variability and subjective ratings of well-being in highly trained swimmers. (2012). https://pubmed.ncbi.nlm.nih.gov/21941017/ DOI: 10.1123/ijspp.7.1.33
Complete structured claim and evidence
Immersion was associated with likely to very likely greater perceived quality of sleep on days 2 to 4 compared with the control week.
Cold water immersion → Perceived sleep quality source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/21941017.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "0cd5dfad3441e660d67198cf010e5fa160936cb66c37b129b575d29d74940910", "start_char": 0, "end_char": 1567, "text_sha256": "0cd5dfad3441e660d67198cf010e5fa160936cb66c37b129b575d29d74940910"}
experimental_model
Eight highly trained swimmers over two matched training weeks in randomised order
exposure
5 minutes of seated recovery at 15 degrees C after the last training session each day
limitations
A small crossover in elite athletes using magnitude-based inference. Sleep quality is self-reported.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
The swimmers reported sleeping better on the cold weeks.
primary_references
[cold-p21941017] Effect of daily cold water immersion on heart rate variability and subjective ratings of well-being in highly trained swimmers. (2012). https://pubmed.ncbi.nlm.nih.gov/21941017/ DOI: 10.1123/ijspp.7.1.33
tissue_or_cell_type
Autonomic nervous system and sleep
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 780–791
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Eight highly trained swimmers over two matched training weeks in randomised order · source_derived_draft · unverified_draft
### cold-sleep-quality Immersion was associated with likely to very likely greater perceived quality of sleep on days 2 to 4 compared with the control week. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The swimmers reported sleeping better on the cold weeks. organism: Human tissue_or_cell_type: Autonomic nervous system and sleep experimental_model: Eight highly trained swimmers over two matched training weeks in randomised order limitations: A small crossover in elite athletes using magnitude-based inference. Sleep quality is self-reported. exposure: 5 minutes of seated recovery at 15 degrees C after the last training session each day evidence_span: {"source_cache": "artifacts/cold-research/21941017.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "0cd5dfad3441e660d67198cf010e5fa160936cb66c37b129b575d29d74940910", "start_char": 0, "end_char": 1567, "text_sha256": "0cd5dfad3441e660d67198cf010e5fa160936cb66c37b129b575d29d74940910"} [cold-p21941017] Effect of daily cold water immersion on heart rate variability and subjective ratings of well-being in highly trained swimmers. (2012). https://pubmed.ncbi.nlm.nih.gov/21941017/ DOI: 10.1123/ijspp.7.1.33
Complete structured claim and evidence
Pooled analysis of nine randomised controlled trials found cold water immersion slightly better than passive recovery for muscle soreness immediately and at delayed time points, with water temperature between 10 and 15 degrees C and immersion time between 10 and 15 minutes giving the best results.
Cold water immersion → Protocol-specified postexercise muscle soreness source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/26581833.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "11e1ee0c7217e7570812ce9fe4c742d8a089a555700ecb9df3b378fe73acd968", "start_char": 0, "end_char": 1958, "text_sha256": "11e1ee0c7217e7570812ce9fe4c742d8a089a555700ecb9df3b378fe73acd968"}
experimental_model
Systematic review and meta-analysis of nine randomised controlled trials against passive recovery
exposure
Cold water immersion at varied temperatures and durations after exercise
limitations
A meta-analysis of a small number of trials, recorded as a review. The dose-response is derived from subgroup comparison, not from a trial that varied dose directly.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
It helps soreness a little, and the best window is about ten to fifteen minutes at ten to fifteen degrees.
primary_references
[cold-p26581833] Can Water Temperature and Immersion Time Influence the Effect of Cold Water Immersion on Muscle Soreness? A Systematic Review and Meta-Analysis. (2016). https://pubmed.ncbi.nlm.nih.gov/26581833/ DOI: 10.1007/s40279-015-0431-7
tissue_or_cell_type
Skeletal muscle
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 793–804
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Systematic review and meta-analysis of nine randomised controlled trials against passive recovery · source_derived_draft · unverified_draft
### cold-soreness-meta-analysis Pooled analysis of nine randomised controlled trials found cold water immersion slightly better than passive recovery for muscle soreness immediately and at delayed time points, with water temperature between 10 and 15 degrees C and immersion time between 10 and 15 minutes giving the best results. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: It helps soreness a little, and the best window is about ten to fifteen minutes at ten to fifteen degrees. organism: Human tissue_or_cell_type: Skeletal muscle experimental_model: Systematic review and meta-analysis of nine randomised controlled trials against passive recovery limitations: A meta-analysis of a small number of trials, recorded as a review. The dose-response is derived from subgroup comparison, not from a trial that varied dose directly. exposure: Cold water immersion at varied temperatures and durations after exercise evidence_span: {"source_cache": "artifacts/cold-research/26581833.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "11e1ee0c7217e7570812ce9fe4c742d8a089a555700ecb9df3b378fe73acd968", "start_char": 0, "end_char": 1958, "text_sha256": "11e1ee0c7217e7570812ce9fe4c742d8a089a555700ecb9df3b378fe73acd968"} [cold-p26581833] Can Water Temperature and Immersion Time Influence the Effect of Cold Water Immersion on Muscle Soreness? A Systematic Review and Meta-Analysis. (2016). https://pubmed.ncbi.nlm.nih.gov/26581833/ DOI: 10.1007/s40279-015-0431-7
Complete structured claim and evidence
Strength and muscle mass increased more with active recovery than with cold water immersion, with isokinetic work up 19%, type II fibre cross-sectional area up 17% and myonuclei per fibre up 26% in the active recovery group but not the immersion group.
Cold water immersion → Skeletal muscle fibre hypertrophy source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/26174323.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "91eff53ecc4779637af3d6fd47a67892729e3a896fdc8738f69d1c7936b4787d", "start_char": 0, "end_char": 1595, "text_sha256": "91eff53ecc4779637af3d6fd47a67892729e3a896fdc8738f69d1c7936b4787d"}
experimental_model
Twelve weeks of strength training in 21 men with immersion or active recovery, plus a biopsy study in nine men
exposure
10 minutes of cold water immersion after each training session, twice weekly for 12 weeks
limitations
A randomised training study with muscle biopsies. It measures long-term adaptation rather than acute recovery, which is why it can disagree with the soreness literature without contradicting it.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Twelve weeks of plunging after lifting left people smaller and weaker than not plunging.
primary_references
[cold-p26174323] Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training. (2015). https://pubmed.ncbi.nlm.nih.gov/26174323/ DOI: 10.1113/jp270570
tissue_or_cell_type
Skeletal muscle
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 806–817
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Twelve weeks of strength training in 21 men with immersion or active recovery, plus a biopsy study in nine men · source_derived_draft · unverified_draft
### cold-cwi-blunts-hypertrophy Strength and muscle mass increased more with active recovery than with cold water immersion, with isokinetic work up 19%, type II fibre cross-sectional area up 17% and myonuclei per fibre up 26% in the active recovery group but not the immersion group. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Twelve weeks of plunging after lifting left people smaller and weaker than not plunging. organism: Human tissue_or_cell_type: Skeletal muscle experimental_model: Twelve weeks of strength training in 21 men with immersion or active recovery, plus a biopsy study in nine men limitations: A randomised training study with muscle biopsies. It measures long-term adaptation rather than acute recovery, which is why it can disagree with the soreness literature without contradicting it. exposure: 10 minutes of cold water immersion after each training session, twice weekly for 12 weeks evidence_span: {"source_cache": "artifacts/cold-research/26174323.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "91eff53ecc4779637af3d6fd47a67892729e3a896fdc8738f69d1c7936b4787d", "start_char": 0, "end_char": 1595, "text_sha256": "91eff53ecc4779637af3d6fd47a67892729e3a896fdc8738f69d1c7936b4787d"} [cold-p26174323] Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training. (2015). https://pubmed.ncbi.nlm.nih.gov/26174323/ DOI: 10.1113/jp270570
Complete structured claim and evidence
Satellite cells expressing NCAM and Pax7 increased 24 to 48 hours after exercise with active recovery, and numbers were greater after active recovery than after immersion, while phosphorylation of p70S6 kinase at Thr421/Ser424 increased after exercise in both conditions but was greater after active recovery.
Cold water immersion → Muscle satellite cells source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/26174323.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "91eff53ecc4779637af3d6fd47a67892729e3a896fdc8738f69d1c7936b4787d", "start_char": 0, "end_char": 1595, "text_sha256": "91eff53ecc4779637af3d6fd47a67892729e3a896fdc8738f69d1c7936b4787d"}
experimental_model
Twelve weeks of strength training in 21 men with immersion or active recovery, plus a biopsy study in nine men
exposure
10 minutes of cold water immersion after each training session, twice weekly for 12 weeks
limitations
A randomised training study with muscle biopsies. It measures long-term adaptation rather than acute recovery, which is why it can disagree with the soreness literature without contradicting it.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
The repair cells that build new muscle showed up in smaller numbers after the cold.
primary_references
[cold-p26174323] Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training. (2015). https://pubmed.ncbi.nlm.nih.gov/26174323/ DOI: 10.1113/jp270570
tissue_or_cell_type
Skeletal muscle
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 819–830
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Twelve weeks of strength training in 21 men with immersion or active recovery, plus a biopsy study in nine men · source_derived_draft · unverified_draft
### cold-cwi-satellite-cells Satellite cells expressing NCAM and Pax7 increased 24 to 48 hours after exercise with active recovery, and numbers were greater after active recovery than after immersion, while phosphorylation of p70S6 kinase at Thr421/Ser424 increased after exercise in both conditions but was greater after active recovery. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The repair cells that build new muscle showed up in smaller numbers after the cold. organism: Human tissue_or_cell_type: Skeletal muscle experimental_model: Twelve weeks of strength training in 21 men with immersion or active recovery, plus a biopsy study in nine men limitations: A randomised training study with muscle biopsies. It measures long-term adaptation rather than acute recovery, which is why it can disagree with the soreness literature without contradicting it. exposure: 10 minutes of cold water immersion after each training session, twice weekly for 12 weeks evidence_span: {"source_cache": "artifacts/cold-research/26174323.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "91eff53ecc4779637af3d6fd47a67892729e3a896fdc8738f69d1c7936b4787d", "start_char": 0, "end_char": 1595, "text_sha256": "91eff53ecc4779637af3d6fd47a67892729e3a896fdc8738f69d1c7936b4787d"} [cold-p26174323] Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training. (2015). https://pubmed.ncbi.nlm.nih.gov/26174323/ DOI: 10.1113/jp270570
Complete structured claim and evidence
Improvements in one-repetition maximum leg press were similar between immersion and control groups, whereas increases in type II muscle fibre cross-sectional area were attenuated with immersion.
Cold water immersion → Skeletal muscle strength source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/31513450.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "f39d3b6bef4879805e7aab7b14df67921ac12765af5d4466836936039ad7a872", "start_char": 0, "end_char": 2195, "text_sha256": "f39d3b6bef4879805e7aab7b14df67921ac12765af5d4466836936039ad7a872"}
experimental_model
Sixteen men completing seven weeks of whole-body resistance training with immersion or passive recovery
exposure
15 minutes at 10 degrees C after each session, three days a week for seven weeks
limitations
A second training study with molecular endpoints. It reproduces the fibre-size result but not the strength result, which is the disagreement recorded in this collection.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Here the cold cost fibre size but not the weight people could lift.
primary_references
[cold-p31513450] Cold water immersion attenuates anabolic signaling and skeletal muscle fiber hypertrophy, but not strength gain, following whole-body resistance training. (2019). https://pubmed.ncbi.nlm.nih.gov/31513450/ DOI: 10.1152/japplphysiol.00127.2019
tissue_or_cell_type
Skeletal muscle
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 832–843
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Sixteen men completing seven weeks of whole-body resistance training with immersion or passive recovery · source_derived_draft · unverified_draft
### cold-cwi-strength-preserved Improvements in one-repetition maximum leg press were similar between immersion and control groups, whereas increases in type II muscle fibre cross-sectional area were attenuated with immersion. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Here the cold cost fibre size but not the weight people could lift. organism: Human tissue_or_cell_type: Skeletal muscle experimental_model: Sixteen men completing seven weeks of whole-body resistance training with immersion or passive recovery limitations: A second training study with molecular endpoints. It reproduces the fibre-size result but not the strength result, which is the disagreement recorded in this collection. exposure: 15 minutes at 10 degrees C after each session, three days a week for seven weeks evidence_span: {"source_cache": "artifacts/cold-research/31513450.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "f39d3b6bef4879805e7aab7b14df67921ac12765af5d4466836936039ad7a872", "start_char": 0, "end_char": 2195, "text_sha256": "f39d3b6bef4879805e7aab7b14df67921ac12765af5d4466836936039ad7a872"} [cold-p31513450] Cold water immersion attenuates anabolic signaling and skeletal muscle fiber hypertrophy, but not strength gain, following whole-body resistance training. (2019). https://pubmed.ncbi.nlm.nih.gov/31513450/ DOI: 10.1152/japplphysiol.00127.2019
Complete structured claim and evidence
Post-exercise mTORC1 signalling measured as rps6 phosphorylation was blunted at 1 and 48 hours after training, basal FOXO1 protein content increased 1.3-fold, and training-induced increases in heat shock protein 27 were attenuated with reduced total heat shock protein 72.
Cold water immersion → Ribosomal protein S6 phosphorylation source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/31513450.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "f39d3b6bef4879805e7aab7b14df67921ac12765af5d4466836936039ad7a872", "start_char": 0, "end_char": 2195, "text_sha256": "f39d3b6bef4879805e7aab7b14df67921ac12765af5d4466836936039ad7a872"}
experimental_model
Sixteen men completing seven weeks of whole-body resistance training with immersion or passive recovery
exposure
15 minutes at 10 degrees C after each session, three days a week for seven weeks
limitations
A second training study with molecular endpoints. It reproduces the fibre-size result but not the strength result, which is the disagreement recorded in this collection.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
The building signal was turned down, the breakdown marker went up, and the muscle stress proteins did not accumulate.
primary_references
[cold-p31513450] Cold water immersion attenuates anabolic signaling and skeletal muscle fiber hypertrophy, but not strength gain, following whole-body resistance training. (2019). https://pubmed.ncbi.nlm.nih.gov/31513450/ DOI: 10.1152/japplphysiol.00127.2019
tissue_or_cell_type
Skeletal muscle
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 845–856
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Sixteen men completing seven weeks of whole-body resistance training with immersion or passive recovery · source_derived_draft · unverified_draft
### cold-cwi-anabolic-catabolic Post-exercise mTORC1 signalling measured as rps6 phosphorylation was blunted at 1 and 48 hours after training, basal FOXO1 protein content increased 1.3-fold, and training-induced increases in heat shock protein 27 were attenuated with reduced total heat shock protein 72. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The building signal was turned down, the breakdown marker went up, and the muscle stress proteins did not accumulate. organism: Human tissue_or_cell_type: Skeletal muscle experimental_model: Sixteen men completing seven weeks of whole-body resistance training with immersion or passive recovery limitations: A second training study with molecular endpoints. It reproduces the fibre-size result but not the strength result, which is the disagreement recorded in this collection. exposure: 15 minutes at 10 degrees C after each session, three days a week for seven weeks evidence_span: {"source_cache": "artifacts/cold-research/31513450.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "f39d3b6bef4879805e7aab7b14df67921ac12765af5d4466836936039ad7a872", "start_char": 0, "end_char": 2195, "text_sha256": "f39d3b6bef4879805e7aab7b14df67921ac12765af5d4466836936039ad7a872"} [cold-p31513450] Cold water immersion attenuates anabolic signaling and skeletal muscle fiber hypertrophy, but not strength gain, following whole-body resistance training. (2019). https://pubmed.ncbi.nlm.nih.gov/31513450/ DOI: 10.1152/japplphysiol.00127.2019
Complete structured claim and evidence
Ten days of cold acclimation at 14 to 15 degrees C increased peripheral insulin sensitivity by about 43% in eight people with type 2 diabetes.
Cold water immersion → Peripheral insulin sensitivity source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/26147760.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "ec2d7942d906f2c11c73487b4afb7682386a7b5759541dde161dde72787503c9", "start_char": 0, "end_char": 451, "text_sha256": "ec2d7942d906f2c11c73487b4afb7682386a7b5759541dde161dde72787503c9"}
experimental_model
Eight subjects with type 2 diabetes acclimated to 14 to 15 degrees C for ten days
exposure
Ten days of cold acclimation at 14 to 15 degrees C
limitations
A small uncontrolled intervention in patients. The effect ran through muscle GLUT4 rather than brown fat, which is the opposite of the expected route.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Ten days of cold made these patients markedly more sensitive to insulin.
primary_references
[cold-p26147760] Short-term cold acclimation improves insulin sensitivity in patients with type 2 diabetes mellitus. (2015). https://pubmed.ncbi.nlm.nih.gov/26147760/ DOI: 10.1038/nm.3891
tissue_or_cell_type
Skeletal muscle and brown adipose tissue
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 858–869
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Eight subjects with type 2 diabetes acclimated to 14 to 15 degrees C for ten days · source_derived_draft · unverified_draft
### cold-cold-insulin-sensitivity Ten days of cold acclimation at 14 to 15 degrees C increased peripheral insulin sensitivity by about 43% in eight people with type 2 diabetes. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Ten days of cold made these patients markedly more sensitive to insulin. organism: Human tissue_or_cell_type: Skeletal muscle and brown adipose tissue experimental_model: Eight subjects with type 2 diabetes acclimated to 14 to 15 degrees C for ten days limitations: A small uncontrolled intervention in patients. The effect ran through muscle GLUT4 rather than brown fat, which is the opposite of the expected route. exposure: Ten days of cold acclimation at 14 to 15 degrees C evidence_span: {"source_cache": "artifacts/cold-research/26147760.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "ec2d7942d906f2c11c73487b4afb7682386a7b5759541dde161dde72787503c9", "start_char": 0, "end_char": 451, "text_sha256": "ec2d7942d906f2c11c73487b4afb7682386a7b5759541dde161dde72787503c9"} [cold-p26147760] Short-term cold acclimation improves insulin sensitivity in patients with type 2 diabetes mellitus. (2015). https://pubmed.ncbi.nlm.nih.gov/26147760/ DOI: 10.1038/nm.3891
Complete structured claim and evidence
Basal skeletal muscle GLUT4 translocation markedly increased without effects on insulin signalling or AMPK activation, and with only a minor increase in brown adipose glucose uptake.
Cold water immersion → Basal skeletal-muscle GLUT4 translocation source_derived_draftungraded
Experimental context and source evidence
evidence_span
{"source_cache": "artifacts/cold-research/26147760.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "ec2d7942d906f2c11c73487b4afb7682386a7b5759541dde161dde72787503c9", "start_char": 0, "end_char": 451, "text_sha256": "ec2d7942d906f2c11c73487b4afb7682386a7b5759541dde161dde72787503c9"}
experimental_model
Eight subjects with type 2 diabetes acclimated to 14 to 15 degrees C for ten days
exposure
Ten days of cold acclimation at 14 to 15 degrees C
limitations
A small uncontrolled intervention in patients. The effect ran through muscle GLUT4 rather than brown fat, which is the opposite of the expected route.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
The glucose door opened in muscle, not in brown fat, and not through the usual signalling.
primary_references
[cold-p26147760] Short-term cold acclimation improves insulin sensitivity in patients with type 2 diabetes mellitus. (2015). https://pubmed.ncbi.nlm.nih.gov/26147760/ DOI: 10.1038/nm.3891
tissue_or_cell_type
Skeletal muscle and brown adipose tissue
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 871–882
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Eight subjects with type 2 diabetes acclimated to 14 to 15 degrees C for ten days · source_derived_draft · unverified_draft
### cold-cold-glut4-route Basal skeletal muscle GLUT4 translocation markedly increased without effects on insulin signalling or AMPK activation, and with only a minor increase in brown adipose glucose uptake. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The glucose door opened in muscle, not in brown fat, and not through the usual signalling. organism: Human tissue_or_cell_type: Skeletal muscle and brown adipose tissue experimental_model: Eight subjects with type 2 diabetes acclimated to 14 to 15 degrees C for ten days limitations: A small uncontrolled intervention in patients. The effect ran through muscle GLUT4 rather than brown fat, which is the opposite of the expected route. exposure: Ten days of cold acclimation at 14 to 15 degrees C evidence_span: {"source_cache": "artifacts/cold-research/26147760.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "ec2d7942d906f2c11c73487b4afb7682386a7b5759541dde161dde72787503c9", "start_char": 0, "end_char": 451, "text_sha256": "ec2d7942d906f2c11c73487b4afb7682386a7b5759541dde161dde72787503c9"} [cold-p26147760] Short-term cold acclimation improves insulin sensitivity in patients with type 2 diabetes mellitus. (2015). https://pubmed.ncbi.nlm.nih.gov/26147760/ DOI: 10.1038/nm.3891
Complete structured claim and evidence
Cold exposure that induced brown adipose activity raised plasma noradrenaline and dopamine and improved peripheral glucose uptake and insulin sensitivity by about 20%, while first-phase insulin response remained stable and specific plasma fatty acids changed, with lignoceric acid rising and eicosanoic, nervonic and behenic acids falling.
Cold water immersion → Peripheral insulin sensitivity source_derived_draftungraded
Experimental context and source evidence
evidence_span
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experimental_model
Fifteen healthy men in a cross-balanced repeated within-subject study with a water-perfused suit
exposure
Moderate cold at 18.06 degrees C with shivering excluded, versus thermoneutral 22 degrees C
limitations
Shivering was deliberately excluded, so the effect is attributable to non-shivering mechanisms. First-phase insulin response was unchanged, separating sensitivity from secretion.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Human
plain_language
Cold improved how the body handles glucose without changing how much insulin the pancreas released.
primary_references
[cold-p28945846] Cold-Induced Brown Adipose Tissue Activity Alters Plasma Fatty Acids and Improves Glucose Metabolism in Men. (2017). https://pubmed.ncbi.nlm.nih.gov/28945846/ DOI: 10.1210/jc.2017-01250
tissue_or_cell_type
Brown adipose tissue and whole body
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 884–895
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Fifteen healthy men in a cross-balanced repeated within-subject study with a water-perfused suit · source_derived_draft · unverified_draft
### cold-cold-glucose-uptake-men Cold exposure that induced brown adipose activity raised plasma noradrenaline and dopamine and improved peripheral glucose uptake and insulin sensitivity by about 20%, while first-phase insulin response remained stable and specific plasma fatty acids changed, with lignoceric acid rising and eicosanoic, nervonic and behenic acids falling. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Cold improved how the body handles glucose without changing how much insulin the pancreas released. organism: Human tissue_or_cell_type: Brown adipose tissue and whole body experimental_model: Fifteen healthy men in a cross-balanced repeated within-subject study with a water-perfused suit limitations: Shivering was deliberately excluded, so the effect is attributable to non-shivering mechanisms. First-phase insulin response was unchanged, separating sensitivity from secretion. exposure: Moderate cold at 18.06 degrees C with shivering excluded, versus thermoneutral 22 degrees C evidence_span: {"source_cache": "artifacts/cold-research/28945846.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "b399b9e904d28b07a332dbd1664fec903eac6427cb2ea9c9e53d8b3a44d0d6fe", "start_char": 0, "end_char": 1937, "text_sha256": "b399b9e904d28b07a332dbd1664fec903eac6427cb2ea9c9e53d8b3a44d0d6fe"} [cold-p28945846] Cold-Induced Brown Adipose Tissue Activity Alters Plasma Fatty Acids and Improves Glucose Metabolism in Men. (2017). https://pubmed.ncbi.nlm.nih.gov/28945846/ DOI: 10.1210/jc.2017-01250
Complete structured claim and evidence
Cells overexpressing Rbm3 showed a three-fold increase in protein synthesis at both 37 and 32 degrees C, a fraction of Rbm3 associated with 60S ribosomal subunits in an RNA-independent manner, and a microRNA-containing complex was less abundant in those cells.
RNA-binding motif protein 3 / RBM3 cold-shock protein → Global cellular protein synthesis source_derived_draftungraded
Experimental context and source evidence
evidence_span
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experimental_model
Mouse neuroblastoma cells overexpressing Rbm3 as a c-Myc fusion protein at 37 and 32 degrees C
exposure
Mild hypothermia at 32 degrees C with Rbm3 overexpression
limitations
A cell-culture overexpression study. The microRNA explanation is offered as a possibility by the authors rather than demonstrated.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Mouse cells
plain_language
The cold-induced protein makes cells build more protein, and it sits on the ribosome to do it.
primary_references
[cold-p15684048] Cold stress-induced protein Rbm3 binds 60S ribosomal subunits, alters microRNA levels, and enhances global protein synthesis. (2005). https://pubmed.ncbi.nlm.nih.gov/15684048/ DOI: 10.1073/pnas.0409764102
tissue_or_cell_type
Neuroblastoma cells
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 897–908
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Mouse neuroblastoma cells overexpressing Rbm3 as a c-Myc fusion protein at 37 and 32 degrees C · source_derived_draft · unverified_draft
### cold-rbm3-protein-synthesis Cells overexpressing Rbm3 showed a three-fold increase in protein synthesis at both 37 and 32 degrees C, a fraction of Rbm3 associated with 60S ribosomal subunits in an RNA-independent manner, and a microRNA-containing complex was less abundant in those cells. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: The cold-induced protein makes cells build more protein, and it sits on the ribosome to do it. organism: Mouse cells tissue_or_cell_type: Neuroblastoma cells experimental_model: Mouse neuroblastoma cells overexpressing Rbm3 as a c-Myc fusion protein at 37 and 32 degrees C limitations: A cell-culture overexpression study. The microRNA explanation is offered as a possibility by the authors rather than demonstrated. exposure: Mild hypothermia at 32 degrees C with Rbm3 overexpression evidence_span: {"source_cache": "artifacts/cold-research/15684048.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "662a7c449d01ae63eabee803791ad8154faa37eb62f60ccf58aabc3bd355d7e5", "start_char": 0, "end_char": 1694, "text_sha256": "662a7c449d01ae63eabee803791ad8154faa37eb62f60ccf58aabc3bd355d7e5"} [cold-p15684048] Cold stress-induced protein Rbm3 binds 60S ribosomal subunits, alters microRNA levels, and enhances global protein synthesis. (2005). https://pubmed.ncbi.nlm.nih.gov/15684048/ DOI: 10.1073/pnas.0409764102
Complete structured claim and evidence
Cooling induces loss of synaptic contacts which reform on rewarming, and the capacity to regenerate synapses after cooling declined in prion-infected and 5XFAD mice in parallel with loss of RBM3 induction.
RNA-binding motif protein 3 / RBM3 cold-shock protein → Structural synapse regeneration after cooling and rewarming source_derived_draftungraded
Experimental context and source evidence
evidence_span
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experimental_model
Cooled laboratory rodents and mouse models of prion disease and Alzheimer-type neurodegeneration
exposure
Artificial cooling with rewarming; RBM3 overexpression or knockdown
limitations
A strong causal design in disease models, using both overexpression and knockdown. It is cooling of anaesthetised rodents, not cold water immersion of a person.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Mouse
plain_language
Cooling strips synapses and rewarming rebuilds them, unless this cold protein fails to appear.
primary_references
[cold-p25607368] RBM3 mediates structural plasticity and protective effects of cooling in neurodegeneration. (2015). https://pubmed.ncbi.nlm.nih.gov/25607368/ DOI: 10.1038/nature14142
tissue_or_cell_type
Hippocampus and synapses
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 910–921
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Cooled laboratory rodents and mouse models of prion disease and Alzheimer-type neurodegeneration · source_derived_draft · unverified_draft
### cold-rbm3-synapse-regeneration Cooling induces loss of synaptic contacts which reform on rewarming, and the capacity to regenerate synapses after cooling declined in prion-infected and 5XFAD mice in parallel with loss of RBM3 induction. Condition category: normal nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Cooling strips synapses and rewarming rebuilds them, unless this cold protein fails to appear. organism: Mouse tissue_or_cell_type: Hippocampus and synapses experimental_model: Cooled laboratory rodents and mouse models of prion disease and Alzheimer-type neurodegeneration limitations: A strong causal design in disease models, using both overexpression and knockdown. It is cooling of anaesthetised rodents, not cold water immersion of a person. exposure: Artificial cooling with rewarming; RBM3 overexpression or knockdown evidence_span: {"source_cache": "artifacts/cold-research/25607368.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "d5cf22cc43a38b28c13d58f29dc4ada326eb6617d86ea4a704638c675406cf48", "start_char": 0, "end_char": 2081, "text_sha256": "d5cf22cc43a38b28c13d58f29dc4ada326eb6617d86ea4a704638c675406cf48"} [cold-p25607368] RBM3 mediates structural plasticity and protective effects of cooling in neurodegeneration. (2015). https://pubmed.ncbi.nlm.nih.gov/25607368/ DOI: 10.1038/nature14142
Complete structured claim and evidence
Enhanced RBM3 expression, achieved either by hypothermia before the loss of the response or by lentiviral delivery, restored synapse reassembly, gave sustained synaptic protection, prevented behavioural deficits and neuronal loss and significantly prolonged survival, whereas RBM3 knockdown exacerbated synapse loss, accelerated disease and prevented the neuroprotective effects of cooling.
RNA-binding motif protein 3 / RBM3 cold-shock protein → Survival in prion-infected and 5XFAD mouse models source_derived_draftungraded
Experimental context and source evidence
availability_state
machinery_impairment Imported condition classification; unverified.
evidence_span
{"source_cache": "artifacts/cold-research/25607368.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "d5cf22cc43a38b28c13d58f29dc4ada326eb6617d86ea4a704638c675406cf48", "start_char": 0, "end_char": 2081, "text_sha256": "d5cf22cc43a38b28c13d58f29dc4ada326eb6617d86ea4a704638c675406cf48"}
experimental_model
Cooled laboratory rodents and mouse models of prion disease and Alzheimer-type neurodegeneration
exposure
Artificial cooling with rewarming; RBM3 overexpression or knockdown
limitations
A strong causal design in disease models, using both overexpression and knockdown. It is cooling of anaesthetised rodents, not cold water immersion of a person.
nutrient_topic
Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Cold water immersion
organism
Mouse
plain_language
Raising the cold protein protected the brain and extended life; removing it cancelled the benefit of cooling itself.
primary_references
[cold-p25607368] RBM3 mediates structural plasticity and protective effects of cooling in neurodegeneration. (2015). https://pubmed.ncbi.nlm.nih.gov/25607368/ DOI: 10.1038/nature14142
tissue_or_cell_type
Hippocampus and synapses
trigger_kind
machinery_impairment Imported condition classification; unverified.
Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19) · lines 923–934
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Cooled laboratory rodents and mouse models of prion disease and Alzheimer-type neurodegeneration · source_derived_draft · unverified_draft
### cold-rbm3-neuroprotection Enhanced RBM3 expression, achieved either by hypothermia before the loss of the response or by lentiviral delivery, restored synapse reassembly, gave sustained synaptic protection, prevented behavioural deficits and neuronal loss and significantly prolonged survival, whereas RBM3 knockdown exacerbated synapse loss, accelerated disease and prevented the neuroprotective effects of cooling. Condition category: machinery_impairment nutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Raising the cold protein protected the brain and extended life; removing it cancelled the benefit of cooling itself. organism: Mouse tissue_or_cell_type: Hippocampus and synapses experimental_model: Cooled laboratory rodents and mouse models of prion disease and Alzheimer-type neurodegeneration limitations: A strong causal design in disease models, using both overexpression and knockdown. It is cooling of anaesthetised rodents, not cold water immersion of a person. exposure: Artificial cooling with rewarming; RBM3 overexpression or knockdown evidence_span: {"source_cache": "artifacts/cold-research/25607368.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "d5cf22cc43a38b28c13d58f29dc4ada326eb6617d86ea4a704638c675406cf48", "start_char": 0, "end_char": 2081, "text_sha256": "d5cf22cc43a38b28c13d58f29dc4ada326eb6617d86ea4a704638c675406cf48"} [cold-p25607368] RBM3 mediates structural plasticity and protective effects of cooling in neurodegeneration. (2015). https://pubmed.ncbi.nlm.nih.gov/25607368/ DOI: 10.1038/nature14142
Complete structured claim and evidence

Availability and dependencies

Each situation shows the normal role first, then what the sources report under a specific condition. A shortfall in the diet, a fault in the machinery, and a low blood reading are kept separate because they are not the same thing.

When the cold channel is missing or blocked

Condition: machinery_impairment · TRPM8 deletion in mice, or the selective antagonist M8-B.

Normal role: TRPM8 opens below about 26 degrees C and reports cooling from the skin.

Recorded consequence: Cold-evoked firing and cold discrimination are profoundly diminished, and in the rat the autonomic and behavioural cold defences fail so that core temperature falls.

Scope: Mouse and rat cold defence

Reading an arrhythmia during cold submersion

Condition: biomarker_context · Submersion with breath holding, and the release of breath holding.

Normal role: The cold shock response speeds the heart while the diving response slows it.

Recorded consequence: Arrhythmias are common in healthy volunteers, and the proposed cause is the conflict itself rather than either response alone.

Scope: Human volunteer submersion studies

When the heat-producing protein is absent

Condition: machinery_impairment · UCP1 ablation in mice.

Normal role: UCP1 uncouples the mitochondrial proton gradient in brown fat and produces heat without shivering.

Recorded consequence: Adaptive non-shivering thermogenesis is not recruited at all and the animal survives by shivering instead; at thermoneutrality the same ablation produces obesity.

Scope: Mouse cold acclimation and thermoneutral housing

When ambient temperature hides the effect

Condition: machinery_impairment · Housing UCP1-ablated mice at thermoneutrality rather than in mild cold.

Normal role: UCP1 mediates both cold and diet-induced adrenergic thermogenesis.

Recorded consequence: Obesity appears that is invisible at ordinary housing temperature, and diet-induced thermogenesis is abolished.

Scope: Mouse metabolic studies

When the cold-shock protein cannot be induced

Condition: machinery_impairment · RBM3 knockdown, or the failure of RBM3 induction seen in neurodegenerative disease models.

Normal role: Cooling induces RBM3, which supports synapse reassembly on rewarming.

Recorded consequence: Synapse loss is exacerbated, disease accelerates, and the protective effect of cooling itself is prevented.

Scope: Mouse prion and 5XFAD models

The sources

Every document behind this chapter is preserved word for word. Open one to read it in full with its recorded conflicts marked in place.

Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19)AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · unverified_draftRead preserved source

Recorded disagreements

Where two sources say different things, both are kept and the difference is explained. You can discuss a disagreement or propose a mechanism that might account for it.

Does cold water immersion after resistance training cost strength, or only fibre size?Two randomised training studies agree that post-exercise immersion attenuates type II fibre hypertrophy and blunts anabolic signalling. They disagree on whether strength follows: a twelve-week study found strength and muscle mass increased more with active recovery, while a seven-week whole-body study found one-repetition maximum leg press improvements similar between groups despite attenuated fibre growth. Training duration, exercise selection, the comparison condition (active versus passive recovery) and the strength test differ between them. Which difference accounts for the disagreement is not established.Read the recorded disagreement
Does repeated cold immersion change the catecholamine system, or not?One study of winter swimmers during a one-hour immersion at 13 degrees C attributes more than a quarter of cold thermogenesis to adrenaline and finds an altered thermoregulatory threshold in adapted swimmers. A seasonal follow-up of winter swimmers and controls found plasma noradrenaline and adrenaline falling from autumn to spring with no significant difference between swimmers and controls, and concluded no clear effect of winter swimming as such. The two measure different things: the acute response during an immersion, and the resting baseline across a season. That difference may account for the disagreement, but neither study measured the other quantity, and it is not established here.Read the recorded disagreement

Open questions in this collection

Questions the curators could not answer from the sources in front of them, kept here with the reason each one is still open. These are gaps in this collection, not findings or proof that no one has studied them.

Whether the sixfold rise in plasma noradrenaline during cold immersion measurably draws on copper, vitamin C or iron status, given that the three enzymes of the pathway require them.The enzyme chemistry and the human immersion measurements are separate records here. No study in this collection measured a nutrient status during or after repeated cold exposure.
Whether the higher resting antioxidant enzyme activity of winter swimmers is caused by cold exposure or by self-selection.The winter swimmer antioxidant study is cross-sectional with no randomisation and no pre-exposure baseline.
Whether the insulin sensitivity gain from days of mild cold acclimation is reproduced by brief cold water immersion.The acclimation studies used ten days at 14 to 15 degrees C or hours in a perfused suit; no record here tests a short immersion protocol against a glucose endpoint.
Whether repeated cold water immersion induces RBM3 in humans at temperatures the body actually reaches.The RBM3 records are rodent cooling and cell culture at 32 degrees C; core temperature in the human immersion records fell far less than that.

Chapters are assembled from supplied drafts and curated literature summaries. Statements remain unverified against the primary studies, and the ledger is not medical advice.

Evidence, AI assistance and curation standards

Cold water immersion

The mechanisms

Cultured sensory neurons and intact sensory nerve fibres from TRPM8-deficient mice showed profoundly diminished responses to cold, demonstrating an essential and predominant role for TRPM8 in thermosensation over a wide range of cold temperatures.

TRPM8-deficient animals showed clear behavioural deficits in discriminating between cold and warm surfaces and in responding to evaporative cooling, while still avoiding surfaces below 10 degrees C with reduced efficiency.

M8-B decreased deep body temperature in Trpm8-positive mice and rats but not in Trpm8-null mice, and intravenous administration was more effective than intrathecal or intracerebroventricular, indicating a peripheral action.

M8-B affected all thermoeffectors studied, including thermal preference, tail-skin vasoconstriction and brown fat thermogenesis, suggesting that TRPM8 is a universal cold receptor in the thermoregulation system, and it attenuated cold-induced c-Fos expression in the lateral parabrachial nucleus.

The review concludes that the cold-shock response can result in death or serious incapacitation long before general hypothermia develops, and is probably responsible for the majority of annual open-water immersion deaths.

Immersion at thermoneutral 32 degrees C did not change rectal temperature or metabolic rate but lowered heart rate by 15% and blood pressure by 11 to 12%, lowered plasma renin activity by 46%, cortisol by 34% and aldosterone by 17%, and increased diuresis by 107%.

Immersion at 14 degrees C lowered rectal temperature and increased metabolic rate by 350%, with heart rate and systolic and diastolic blood pressure rising by 5, 7 and 8%.

Plasma noradrenaline and dopamine concentrations increased by 530% and 250% at 14 degrees C, while plasma adrenaline concentrations remained unchanged and cortisol tended to decrease.

Brown adipose tissue activity was observed in 23 of 24 subjects during cold exposure at 16 degrees C but not under thermoneutral conditions.

Cold-activated brown adipose tissue activity was significantly lower in overweight or obese subjects than in lean subjects, with body-mass index and percentage body fat both negatively correlated and resting metabolic rate positively correlated.

Cold exposure activated oxidative metabolism in brown adipose tissue but not in adjoining skeletal muscle or subcutaneous adipose tissue, with substantial non-esterified fatty acid and glucose uptake, and this was associated with an increase in total energy expenditure.

An inverse relationship was found between brown adipose tissue activity and shivering, and brown adipose tissue radio density increased upon cold exposure, indicating reduced triglyceride content.

Cold induced a 12-fold increase in brown adipose tissue glucose uptake accompanied by a doubling of perfusion, with whole-body energy expenditure positively associated with perfusion, whereas insulin enhanced glucose uptake 5-fold independently of perfusion.

UCP1-ablated mice acclimated to 4 degrees C sustained heat production at four times resting levels entirely by shivering, with no substitution by any adaptive non-shivering thermogenic process in muscle or any other organ, and neither UCP2 nor UCP3 could substitute.

At thermoneutrality, UCP1 ablation induced obesity even on control diet and vastly augmented diet-induced obesity, and high-fat diet increased norepinephrine-induced thermogenesis in wild-type but not UCP1-ablated mice, showing diet-induced thermogenesis fully emanates from UCP1 activity.

PGC-1 mRNA expression is dramatically elevated on cold exposure in both brown fat and skeletal muscle, and PGC-1 greatly increases the transcriptional activity of PPARgamma and the thyroid hormone receptor on the UCP1 promoter.

Ectopic expression of PGC-1 in white adipose cells activated expression of UCP1 and key mitochondrial enzymes of the respiratory chain, and increased cellular mitochondrial DNA content.

Type 2 iodothyronine deiodinase is a selenoenzyme, the product of the cAMP-dependent Dio2 gene, which increases 10- to 50-fold during cold stress only in brown adipose tissue.

Cold-exposed Dio2-disrupted mice became hypothermic due to impaired brown adipose thermogenesis despite normal plasma T3 and normal basal UCP1, and survived by compensatory shivering with acute weight loss.

In Dio2-null brown adipocytes the acute norepinephrine-, CL316,243- or forskolin-induced increases in lipolysis, UCP1 mRNA and oxygen consumption were all reduced because of impaired cAMP generation, and all were completely reversed by a single T3 injection 14 hours earlier.

Creatine enhanced respiration in beige-fat mitochondria when ADP was limiting, and cold exposure stimulated mitochondrial creatine kinase activity and induced coordinated expression of creatine metabolism genes in murine beige fat.

Cold exposure increased circulating irisin and FGF21, with irisin secretion induced in proportion to shivering intensity and of similar magnitude to exercise-stimulated secretion.

FNDC5 and FGF21 treatment upregulated human adipocyte brown-fat gene and protein expression and thermogenesis in a depot-specific manner, suggesting a thermogenic cold-activated endocrine axis between muscle and fat.

Brown adipose volume correlated with the change in metabolic heat production during the mild cold phase, and positively correlated with rectal temperature at the end of that phase, which in turn correlated with shivering onset time.

Skeletal muscle mass correlated with baseline metabolic heat production but not with non-shivering thermogenesis, and skin blood flow and skin temperatures did not correlate with non-shivering thermogenesis or brown adipose volume.

Tyrosine hydroxylase is a non-heme iron enzyme that uses molecular oxygen to hydroxylate tyrosine to L-DOPA and tetrahydrobiopterin to 4a-hydroxybiopterin in the rate-limiting step of the catecholamine biosynthetic pathway.

Dopamine beta-hydroxylase specifically binds 8 moles of copper per mole of tetramer, confirmed by radiolabel, atomic absorption, NMR and EPR titration, and catalytic rate increased with copper up to that ratio and was constant thereafter, so this stoichiometry is required for maximal activity.

Below a ratio of eight copper atoms per tetramer, the measured rate of enzymatic catalysis rose in proportion to the copper present rather than being maximal.

Incubation with tyramine produced a time-dependent decrease in reduced intragranular ascorbate proportional to extragranular tyramine concentration over 50 microM to 2 mM.

Winter swimmers showed bradycardia and a greater reduction in plasma volume during cooling, indirectly indicating restriction of heat loss, with only a non-significant increase in subcutaneous fat, and exhibited metabolic, hypothermic and insulative types of cold adaptation together.

Repeated cold air exposure increased the oral metabolic clearance rate of T3 by 5.4 l/day/m2 and the disposal rate by 10.2 nmol/day/m2, and these increases were not dependent on thyrotropin or thyroxine, since they were unchanged in men given replacement T3 whose TSH and T4 fell by about half.

The effect of a single cold water immersion at 14 degrees C for 1 hour on the immune system, monitored immediately after immersion, was minimal.

Negative affect was lower 180 minutes after a single 15-minute immersion at 10 degrees C while positive affect did not change, and cortisol was lower at 180 minutes, whereas serum beta-endorphins did not change throughout the trial.

Forearm vascular conductance was reduced at 15 minutes of immersion and 30 minutes after, and total and antegrade shear stress and the oscillatory shear index were reduced 30 minutes after immersion, with no difference in retrograde shear.

Five minutes of immersion at 15 degrees C after training reduced the usual exercise-induced decrease in parasympathetic activity, with vagal-related heart rate variability likely to very likely improved on days 2 to 5 compared with control.

Immersion was associated with likely to very likely greater perceived quality of sleep on days 2 to 4 compared with the control week.

Pooled analysis of nine randomised controlled trials found cold water immersion slightly better than passive recovery for muscle soreness immediately and at delayed time points, with water temperature between 10 and 15 degrees C and immersion time between 10 and 15 minutes giving the best results.

Strength and muscle mass increased more with active recovery than with cold water immersion, with isokinetic work up 19%, type II fibre cross-sectional area up 17% and myonuclei per fibre up 26% in the active recovery group but not the immersion group.

Improvements in one-repetition maximum leg press were similar between immersion and control groups, whereas increases in type II muscle fibre cross-sectional area were attenuated with immersion.

Post-exercise mTORC1 signalling measured as rps6 phosphorylation was blunted at 1 and 48 hours after training, basal FOXO1 protein content increased 1.3-fold, and training-induced increases in heat shock protein 27 were attenuated with reduced total heat shock protein 72.

Ten days of cold acclimation at 14 to 15 degrees C increased peripheral insulin sensitivity by about 43% in eight people with type 2 diabetes.

Basal skeletal muscle GLUT4 translocation markedly increased without effects on insulin signalling or AMPK activation, and with only a minor increase in brown adipose glucose uptake.

Cells overexpressing Rbm3 showed a three-fold increase in protein synthesis at both 37 and 32 degrees C, a fraction of Rbm3 associated with 60S ribosomal subunits in an RNA-independent manner, and a microRNA-containing complex was less abundant in those cells.

Cooling induces loss of synaptic contacts which reform on rewarming, and the capacity to regenerate synapses after cooling declined in prion-infected and 5XFAD mice in parallel with loss of RBM3 induction.

Availability and dependencies

The sources

Recorded disagreements

Open questions in this collection