Using Deliberate Cold Exposure for Health and Performance

High-Level Overview

In this solo episode, Andrew Huberman explains how deliberate cold exposure affects the brain and body and how to use it for mental resilience, mood and focus, metabolism, recovery from exercise and physical performance. He covers how the body regulates temperature, how cold triggers the release of norepinephrine, epinephrine and dopamine, how it can convert energy-storing white fat into heat-producing beige and brown fat, what the research says about cold after training, and how cooling specific skin surfaces (the palms, soles and upper face) can dramatically increase how much work you can do. He opens with a strong safety message: temperature is a potent stimulus, so consult a physician, progress gradually and look for the minimum effective dose.

The tone is detailed and practical, drawing on Huberman's undergraduate background in a cold physiology lab, and it blends mechanisms with many specific protocols. The episode starts with a bonus study on exercise before focused work, then moves from thermoregulation to mental effects, metabolism, inflammation and performance, and ends with guidance on timing cold exposure around sleep.

The Discussion Explores:

• A study showing 15 minutes of moderate jogging sharpens attention more than meditation before cognitive work
• The daily temperature rhythm and why a cold towel on your torso can make you hotter
• How cold should it be, and why immersion beats showers, which beat cold air
• Building resilience by counting adrenaline "walls," plus mindset, cognitive tasks and movement in the cold
• An 11-minute weekly target, and a study showing 250 percent increases in dopamine
• Brown fat, the Søberg principle (end on cold) and shivering to boost metabolism
• Cold after training, a 52-study meta-analysis, and waiting four hours after strength or hypertrophy work
• Palmar cooling for endurance and strength volume, cold and testosterone, and timing cold around sleep

Deep Dive into Main Ideas

A Bonus Tool: Brief Exercise Before Focused Work

Before getting to cold, Huberman highlights a study by Legrand and colleagues titled "Brief aerobic exercise immediately enhances visual attentional control and perceptual speed." In 101 college students, one group jogged at moderate intensity for 15 minutes (roughly zone 2, where you can talk with some strain) and another did 15 minutes of a mindfulness-style relaxation practice. The joggers reported more energy and completed the Trail Making Tests, which require visually searching a page and connecting numbers (and alternating numbers and letters) in sequence, significantly faster. The meditation group felt calmer but less energetic. Huberman's takeaway: before demanding cognitive work, 15 minutes of moderate exercise may be more valuable than 15 minutes of meditation. The ideal sequence is to get energetic and alert, do the learning or work, and then use meditation or NSDR (non-sleep deep rest) afterward to support plasticity.

The Body's Thermostat and Glabrous Skin

Body temperature follows a daily rhythm. It hits its lowest point, the temperature minimum, about two hours before your usual wake time, rises through the morning into the afternoon, then falls one to three degrees in the evening, a drop that is important for falling and staying asleep. Any cold exposure sits on top of this rhythm.

Huberman then describes a thought experiment: while jogging in 102-degree desert heat, most people would drape a cold towel over their head, neck or torso. That is exactly wrong and can raise core temperature further. The brain's thermostat, the medial preoptic area of the hypothalamus, reads a cold body surface as a cold environment and triggers heating, just as putting ice on a home thermostat would make the heater turn on. The efficient way to cool down is through glabrous skin, meaning the palms, soles of the feet and upper half of the face. Beneath these surfaces are arteriovenous anastomoses, direct connections from arteries to veins that let the body dump heat quickly. He calls this potentially lifesaving knowledge for heatstroke, which is extremely dangerous because the brain and organs can quickly be damaged by excess heat.

How Cold, and What Kind

Huberman separates the goals of cold exposure: mental resilience and stress control, mood and focus via catecholamines (the family of chemicals that includes dopamine, norepinephrine and epinephrine), metabolism, reducing inflammation, and physical performance. He emphasizes the word deliberate. Citing his colleagues David Spiegel and Alia Crum, he notes that choosing to put yourself in a stressful state, and believing it is beneficial, produces different physiological effects than stress imposed on you. This mindset effect is distinct from placebo.

The most common question is how cold. Because cold tolerance varies so much, his rule of thumb is that the temperature "should place your mind into a state of whoa I would really like to get out of this environment but I can stay in safely." That threshold changes from day to day and across the day; cold feels much harder late at night than in the afternoon. He warns that plunging into extremely cold water, such as through a hole in lake ice, can cause cold shock and even death in unprepared people. As for method, immersion up to the neck with hands and feet under is most effective, cold showers are second (and barely studied, since they are hard to standardize), and going outside underdressed is third. Water pulls heat from the body far faster than air. He sets aside cryotherapy chambers because of cost and limited research, and mentions ice vests and ice-pack underwear as options he will not focus on, since cooling the palms, face and soles is far more efficient.

Building Resilience by Climbing Walls

Cold reliably triggers the release of norepinephrine and epinephrine from the adrenal glands, from brain areas such as the locus coeruleus, and elsewhere in the body, no matter how tough or experienced you are. Since everyday stress runs on the same chemicals, deliberate cold lets you practice staying calm and clear-headed while flooded with them. Huberman defines resilience as your prefrontal cortex using willpower to override the reflexes urging you to escape.

One approach is timed progression, like sets and reps: one minute on Monday, 50 percent longer on Wednesday, twice as long on Friday, then continuing to extend time or lower temperature. Its weakness is that you eventually run out of room, because water can only get so cold and you cannot sit in it all day. His preferred method is counting walls, the surges of "I don't want to do this" and the urge to get out. For some people, getting in at all is the first wall. Decide before you start how many walls you will climb that day, such as three or five, noting that each wall arrives when it arrives, and vary the number and temperature over time. This keeps the stimulus effective and mirrors real-life stressors, which arrive unpredictably, such as a text with bad news.

For mindset, he compares it to driving on gravel roads: sometimes you speed through and sometimes you slow down. You can calm yourself with double inhales through the nose and long exhales through the mouth, or lean in and grind it out. Everyone gets short of breath in cold water, and he says frontal cortex function can drop 30 to 80 percent. Doing mental tasks in the cold, like challenging arithmetic, forming full sentences or recalling difficult information, trains your prefrontal cortex to stay online under stress, much like the odd sport of chess boxing. He also points out that sitting perfectly still lets a warm thermal layer form around your body. Moving your limbs, with hands and feet submerged, breaks up that layer and makes the same temperature a much stronger stimulus, so people who sit stoically are shortchanging themselves.

How Often: The 11-Minute Target

A few human studies point to about 11 minutes total per week, split into two to four sessions of a few minutes each, a threshold tied mainly to metabolic effects. Huberman suggests using it as a minimum. Once 11 minutes becomes easy and you rarely hit walls, safely lower the temperature, extend the time or increase frequency. He does cold exposure about three times a week for two to six minutes per session, using the walls method, which totals about 11 to 15 minutes. Consistency and safety matter more than precision. He notes that Navy SEAL training relies on cold water precisely because it offers wide room to adjust duration and temperature, unlike heat, where the margin before injury is small.

Dopamine, Norepinephrine and Mood

Cold is unusual among stressors because it raises dopamine, not just norepinephrine and epinephrine, which is why people feel great afterward even if they hated being in it. Huberman mentions that psychiatrist Anna Lembke describes in her book Dopamine Nation a patient who used cold water exposure as a healthier dopamine source to help stay sober. He details a 2000 study by Šrámek and colleagues in the European Journal of Applied Physiology, in which people sat immersed to the neck for one hour at 32°C (89°F), 20°C (68°F) or 14°C (57.2°F). The 32°C group showed no significant change. The 20°C group's metabolic rate rose 93 percent. The 14°C group's metabolism rose 350 percent, norepinephrine rose 530 percent and dopamine rose 250 percent, and these increases lasted up to two hours afterward, when measurements stopped. Cortisol did not rise significantly.

Huberman says these long-lasting increases likely explain the better mood, energy and focus people report, and that the dopamine increase is comparable to that of addictive substances like nicotine but without the crash. He stresses that he is not recommending an hour of cold, and that shorter, colder exposures have not yet been studied in the same way. Citing Hans Selye's distinction between distress and eustress, he suggests deliberate cold produces eustress: catecholamines rise without much cortisol, which can support health.

Brown Fat, the Søberg Principle and Shivering

A recent study led by Susanna Søberg on young men who swim in winter, titled "Altered Brown Fat Thermal Regulation and Enhanced Cold Induced Thermogenesis in Young Healthy Winter Swimming Men," used about 11 minutes a week of cold immersion, which Søberg told him could be split into two, three or four sessions. It found increased brown fat thermogenesis and a modest but significant rise in metabolism, and participants became more comfortable in the cold. Huberman links this to a Scandinavian saying passed along by his Danish relatives: skip the jacket in fall to prepare for winter. The key mechanism is that norepinephrine binds receptors on white fat cells and activates pathways including UCP1, PPAR-gamma and PGC-1 alpha, increasing mitochondria and changing gene expression so white fat becomes thermogenic beige or brown fat. That fat acts as a furnace that raises daily calorie burn. Babies rely on brown fat because they cannot shiver well, and adults tend to lose it but can rebuild it. Nerves also release norepinephrine directly into fat tissue, not just through the bloodstream. He points readers to a review in Cell on adipose tissue plasticity in health and disease.

He adds several layering tips. Being fasted already raises norepinephrine and epinephrine, which may amplify the effect. Taking about 300 milligrams of caffeine 60 to 120 minutes beforehand increases the availability of dopamine D2/D3 receptors in the striatum, according to a human study, so the dopamine released by the cold can act more strongly. He then names what he calls the Søberg principle: to maximize metabolic benefits, end on cold and let your body reheat on its own rather than jumping into a hot shower or sauna. He admits he often takes a hot shower afterward because metabolism is not his main goal. Shivering adds more: a 2018 Nature study found shivering muscles release succinate, which activates brown fat thermogenesis. A tough but effective routine is to alternate one to three minutes of cold with one to three minutes standing in the air with arms at your sides, not hugging yourself, until you shiver.

Cold for Recovery, Inflammation and Training

If your main goal is muscle growth or strength, Huberman advises avoiding cold water immersion for about four hours after that training, or doing it on a different day. He says it is hard to imagine a brief cold shower erasing gains, though there are few studies on showers. For endurance, sprint, skill or other performance-focused training, he sees no reason in the literature to avoid cold immediately afterward.

He summarizes a meta-analysis of 52 studies titled "Impact of cold water immersion compared with passive recovery following a single bout of strenuous exercise on athletic performance in physically active participants." It found that cold water immersion after high-intensity exercise improved muscular power, reduced soreness and serum creatine kinase (a marker of muscle damage) and improved perceived recovery at 24 hours compared with passive rest, though eccentric exercise did not benefit. It also found that shorter exposures at lower temperatures can be effective. Huberman adds that cold lowers inflammatory cytokines such as IL-6 and raises anti-inflammatory ones such as IL-10, and that because inflammation from hard training can persist for days, extra cold sessions on non-training days can help.

Palmar Cooling for Endurance and Strength

Drawing on the work of his Stanford colleague Craig Heller, Huberman describes a randomized trial on exercise-induced hyperthermia in which subjects walked uphill at 9 to 17 percent incline in heavy clothing in a 40°C (104°F) room. Cooling the palms, soles and upper face let them keep going much longer and brought their temperature down faster than the traditional approach of ice packs on the neck, armpits and groin. The cooling object must not be so cold that it constricts the blood vessels, or the heat-dumping pathways shut down. That is why Heller's group developed the CoolMitt, a glove that circulates water at the right temperature (Huberman has no financial ties to it). Home versions include a bag of frozen blueberries or bottles of cold water with a few ice cubes.

The main benefit is more total work, not a higher single-set maximum. A person who can do 40 dips might, with two minutes of palm cooling between sets, do 40, then 40, then 38 instead of steadily declining. The study "Work volume and strength training responses to resistive exercise improved with periodic heat extraction from the palm" reported a 144 percent increase in pull-up volume over six weeks in experienced subjects, a 22 percent increase in bench press one-rep max over 10 weeks, and especially strong effects for breaking through plateaus. Heller has also observed reduced or eliminated muscle soreness. The mechanism is that pyruvate kinase, an enzyme essential for muscle contraction, only works in a narrow temperature range, so as muscles heat up, their capacity to contract falls. Huberman suggests using palm cooling selectively to push through plateaus, after a proper warm-up.

Cold and Testosterone, and Timing Around Sleep

On the online trend of ice packs or ice underwear on the testicles to raise testosterone, Huberman says he found no controlled study and asks listeners to send one if they know of it. He proposes two plausible mechanisms: a rebound increase in blood flow after vasoconstriction, and the more likely route of cold-induced dopamine increasing luteinizing hormone, which raises testosterone and estrogen. He doubts direct cooling is necessary, since general cold immersion would have the same downstream effect, and warns about potential tissue damage.

Finally, because cold on the body's surface ultimately raises core temperature and alertness, doing it in the morning or midday supports the natural daytime rise. Doing it late in the evening can interfere with the temperature drop needed for sleep. Huberman mentions doing cold exposure at 11 p.m. during a 30-day challenge and still sleeping fine, but he was exhausted on those days. His general advice is to do cold exposure only when you are prepared to be alert for the next one to six hours.

Conclusion

Deliberate cold exposure is a flexible, low-cost tool with wide-ranging effects when used safely and intelligently. The core rules are to get uncomfortably cold but stay safe, aim for about 11 minutes a week, prefer immersion with limbs submerged and moving, and progress by counting walls rather than chasing ever-colder water. It can build resilience, produce large and lasting increases in dopamine and norepinephrine for mood and focus, and convert white fat into metabolism-boosting brown fat, especially if you end on cold and let yourself shiver. It can also speed recovery after high-intensity work, as long as you keep it four hours away from strength and hypertrophy sessions. Palm cooling offers a surprisingly powerful way to do more training volume. For the full detail on the mechanisms and studies, the complete episode is a rich resource.

This is a summary of "Using Deliberate Cold Exposure for Health and Performance" from Huberman Lab, giving you the GIST so you can decide if you want the REST. Listen to the full episode.