Cold showers

Want to experience the benefits of hormesis very directly? Take a cold shower! And don’t just try it once, make it a habit and take cold showers daily.  I have been doing it daily for the past six months and am loving it!

As one form of hydrotherapy, the health benefits of cold water therapy are numerous.  Cold showers provide a gentle form of stress that leads to thermogenesis (internal generation of body heat), turning on the body’s adaptive repair systems to strengthen immunity, enhance pain and stress tolerance, and ward off depression, overcome chronic fatigue syndrome, stop hair loss, and stimulate anti-tumor responses.

Some people advocate starting with a warm shower, and switching over to cool or cold water only at the end of the shower. This is fine, particularly if you are afraid that a pure cold shower would just be too uncomfortable or intolerable.  But I prefer just jumping right in. When you start with cold water, you will experience the phenomenon of cold shock, an involuntary response characterized by a sudden rapid breathing and increased heart rate. This in itself is very beneficial. The extent of cold shock has been shown to decrease with habituation, and exposure to colder water (10C or 50F) appears to be more effective than just cool water (15 C or 59F) in promoting habituation. The habituation itself is what is most beneficial, both objectively and subjectively. There is an analogy here with high intensity resistance exercise and interval training, both of which elevate heart rate and lead to long term adaptations to stress, with improved cardiovascular capacity and athletic performance.

But cold showers provide a different and probably complementary type of habituation to that which results from exercise. A study of winter swimmers compared them with a control group in their physiological response to being immersed in cold water:  Both groups responded to cold water by thermogenesis (internal production of body heat), but the winter swimmers did so by raising their core temperature and did not shiver until much later than the controls, whereas the control subjects responded by shivering to increase their peripheral temperatures. The winter swimmers also tolerated much larger temperature differences and conserved their energy better. Other studies confirm that the benefits of habituation show up only after several weeks of cold showering. For example, adaptation to cold leads to increased output of the beneficial “short term stress” hormones adrenaline and thyroxine, leading to mobilization of fatty acids, and substantial fat loss over a 1-2 week period.

So regular cold showers, like high intensity exercise, and intermittent fasting, appear to provide similar, but not identical hormetic benefits.

But now I’d like to focus on the subjective experience of taking cold showers, something not commented on in many of the studies I’ve read. If you follow my approach and plunge right into a cold shower, you’ll get the initial “cold shock” mentioned above:  a quickened pace of breathing and a pumping heart.  Often I find myself involuntarily smiling or even laughing.  For waking up, this beats caffeine. I keep the water cold the whole time. It helps to brace yourself when entering by gritting your teeth and stiffening your muscles. Go in head first and alternate from back to front to make sure you are getting cold all over, including your hands and arms and any sensitive zones. After about a minute, you’ll find the cold water starts to become more tolerable, and after 2 or 3 minutes you’ll feel your body getting warm by its own efforts. This is thermogenesis. I make a point of staying in the shower until I’m no longer uncomfortable.  I found that at first my hands were the most sensitive part, and now they are no longer as sensitive, so they have habituated.

When I started taking cold showers, I measured the water temperature at around 60 F (16 C), but over time I have reduced this somewhat to 50-55 F (10-13C) as my body has adapted. (You can determine this by bringing into the shower a plastic cup and meat or candy thermometer and collecting some water once the temperature equilibrates).  Of course, depending on where you live and the season, there is a lower limit to how cold you can go, but in general you should be able to get at least as cold as 60F in most places. Also, my cold showers used to be very short, maybe 4 or 5 minutes, but now they last as long as my previous warm showers, perhaps 10 minutes.  I still take the occasional warm shower, perhaps once every week or so, but I prefer the cold ones.

I find that cold showers are great for the mood.  Not only are they physically invigorating, they make you feel alive, vital and ready to take on the day. They stimulate thinking early in the morning. I also believe that they have the effect of slightly raising blood glucose very quickly — by perhaps 10 mg/dl, and thereby have an appetite suppressing effect. Generally, this rise in blood glucose is relatively short in duration, but that’s good enough to prime the pump and get the day started.  This effect of cold showers works well with my practice of skipping breakfast most days and often fasting until dinner.

These effects are apparent with the first cold shower. If you continue the practice for several weeks, you’ll find the psychological benefits are even greater. First and foremost, cold showers appear to have improved my stress tolerance, by buffering emotional reactions. What I mean by this is that bad news, surprises, arguments, or events that would have previously caused a brief surge in adrenaline or an emotional flush, no longer have that effect, or at most have a very attenuated effect.  I think this is a consequence of becoming acclimated to the the adrenaline-producing effect of the cold shock.  A deeper explanation of why cold showers are effective in boosting mood, and why the psychological benefits of cold showers increase the longer and more frequently you take them is addressed in my recent post on the opponent-process theory of emotions.

As with any application of Hormetism, you can experiment with the intensity of cold, the duration, and the frequency of cold showers to improve your tolerance at a tolerable rate.  If you find that your heart is beating uncomfortably fast or you are going numb or experiencing pain of any sort, that’s a good reason to ease into the routine more slowly with water that is not so cold. Check with your doctor first if you have a heart condition, migraines, or pain.  But don’t sell yourself short and rush through a cold shower, because you may find that extending a few more minutes provides the greatest benefits in adapting your body to tolerate stress. Not just cold stress — but physical and emotional stress in general.

January 29, 2012 update:  If you want to take cold showers to the next level, check out this recent article on The Iceman.

February 17, 2014 update:  For details on the hormonal mechanisms of cold-induced thermogenesis and weight loss, see my post on What cold showers and exercise have in common.

July 21, 2014 update:   For hard evidence that cold showers improve stress tolerance by altering cardiac function and the parasympathetic nervous system, see my post on Track your HRV to boost adaptive reserves.


  1. Mike

    Am I the only unlucky dude whose body has rejected the cold showers?
    I began 6 months ago with full cold showers and gradually prolonged them to comfortable 3 minutes. Although I would always feel great and invigorated, I noticed that 30 minutes afterwards chills and cold hands and feet wold set in and I would warm up only inthe afternoon. Autumn came and I found myself very intolerant even of mild cold, so I decided to start with warm water and end with usual 3 minutes of cold but that did not ward off the uncomfortable cold sensations. Finally, on the first winter day I caught a heavy cold, so I had to suspend cold showers completely. After 5 days of inly warm showers, my hands and feet are warm again and I am not nervous out in the cold anymore. Chills are also gone.
    I would like to continue with cold showers but at this point I don’t know if they are really for me. I am 44 yo healthy male 188cm / 80 kg, a bit thin constitution.
    Do you have any advice for me?

    • Todd


      People vary widely in their cold tolerance and ability to turn on thermogenesis. While I think that it’s always possible to adapt to becoming more tolerant to the cold, there are a number of reasons why some people are more cold sensitive, including hypothyroidism, anemia, fibromyalgia or vasoconstriction. People vary in their ability to activate thermogenesis, perhaps due to differences in genetic expression of uncoupling proteins, like thermogenin. People who are very thin and deficient in brown fat often have low thermogenin levels. Interestingly, adding essential fatty acids (such as those found in oily fish and grass fed beef) significantly boosts thermogenin and thermogenesis. Exercise also boosts brown fat and levels of the thermogenic hormones irisin and FGF21, as I detailed in this post:

      What cold showers and exercise have in common

      I suggest the following:
      – Check your thyroid levels to see if you are hypothyroid.
      – Eat fatty fish (salmon, mackerel, eel) and beef or take fish oil supplements
      – Exercise more vigorously, particularly right before or after your cold showers

      Since cold showers did provide you with some benefit, consider following a more moderate version of cold shower therapy, e.g. use lukewarm water or switch to cold water only for the last 30 seconds after your warm shower. If this works, you can very gradually reduce the temperature and prolong the time of the cold.

      Gradualism so often is the secret when “cold turkey” doesn’t work.


      • Mike

        Thank you so much for the advice. Will check and try and report back in a while.

        • Mike

          Hello, as promised, I am reporting back after two months of taking a “modified approach” according to your advice. I reset my cold water exposure back to 30 seconds and began extending it by 5 seconds every month (a snail’s progress or “gradualism”) so I am now at 40 seconds of full cold water (12 degrees Celsius now in winter months) after warm shower. Side-effects which I had described in my original post are now gone, but so is the thrill and that vigour. I am much less prone to catching colds but I still continue to pick up every flu that becomes popular in town (albeit in a very mild form, without fever and never lasting more than a day). The shorter exposure to cold water also did not make me less sensitive to cold temperature as some people have reported.
          So, your advice did work and I wish to thank you. I am now aiming for a full minute in 5-second monthly steps and intend to stop there.

    • Santiago

      I would suggest that you check your blood pressure as it might be low. Taking a .25 tbs of lite salt and .25 tbs of Himalayan salt in .5 L of water might help you with the cold hands and feet.

  2. Hi Todd

    Really interesting post.

    I’ve been cold showering for about a month now and I’m not sure whether I’m seeing any benefits yet except that I generally feel a bit more alert throughout the whole day and it is now less than 5 seconds for my body to not feel the coldness any more.

    I’m wondering if there is a ‘too cold’ temperature for cold showering on a daily basis. I’ve worked out that the water comes out of our tap at about 6 degrees C and as I can’t measure or control any small addition of hot to bring it to the 10 degrees mark, I’ve just left it there.

    Could this be the reason that I’m unable to get past the brain-freeze, ‘ice-cream headache’ that I still get when rinsing my head?
    I’ve read your reply to some other comments about focussing on the sensitive areas, but I’m not sure if you mean just keep the cold on the area constantly until the pain goes away (so hard, brain freeze is cripplingly painful) or to build up gradually.
    I also get a fair bit of serious pain in the distal interphalangeal joints of my little and index fingers on one hand which confuses me.

    Lastly, could there be a valid argument that to start with a hot shower and then switch to cold in an instant could give an even greater cold shock than just jumping in cold?

    Thanks for your post.


    • Todd


      6C – that is indeed cold. (It’s 43F, for those not familiar with the metric system). When I’ve travelled to Finland or Colorado in the winter, I’ve taken such showers, and I love ’em.

      As with everything hormetic, my approach is to aim for discomfort but always stay this side of pain. If you experience pain, you are pushing too far, too fast. I know what you mean about brain freeze. I find the best approach is to dip in and out of the freezing cold water. The in-and-out strategy gives you some time to adapt. At first, keep your head, shoulders or hands in the stream of cold water for short periods of a few seconds, then step back. Do it again and again, gradually increasing how long you stay in. At the first hint of brain freeze or pain, pull out. I’ve found that eventually you can stay in the cold water stream for quite some time — meaning that you have adapted.

      Some people advise starting hot and gradually going colder. I find that actually makes it harder to adapt to the cold, makes the cold less pleasant, and just wastes time. But others find it to be a help, so do whatever works for you.


      • Thanks for the reply Todd.

        I’m at the stage now after more than 4 weeks that my body – back, front, arms and legs etc. take less than 5 seconds to adapt to the cold, it’s only one or two finger joints that protest if I keep that hand in the cold too long.

        I’ll dip my head in and out for shorter periods, I almost made myself vomit yesterday by accident with brain freeze!!

        I was just wondering if the physiological benefit to the ‘cold shock’ could be accentuated by increasing the body temperature in a hot shower first? Our shower goes from hot to cold literally at the flick of a switch and it’s not a gradual transition at all.

        Anyway, thanks for the post, feeling the benefit. 🙂


        • Todd


          I’m not sure there is any evidence that cold shock is enhanced via more “contrast” with a preliminary hot shower. My personal experience is the opposite — starting with a hot shower tends to make the shift to cold easier to tolerate by creating a kind of “buffer”. Some people like this; I see it as delaying the inevitable. I’d rather get right into the cold experience.

          There is another theory that “contrast baths” — alternating between hot and cold — have some kind of benefit to the circulation or lymph glands. I’ve seen no hard evidence to support that theory. Here is one study:


          • Thanks for that link Todd.

            One last question (for the moment), do you know of any hard evidence for cold showering to have a positive effect on diabetes?


            • Todd

              Most definitely!


              “In conclusion, cold-exposed rats are able to mobilize glucose more efficiently than controls, even presenting a clear pattern of molecular resistance to insulin in at least two tissues that act as important targets for insulin action, WAT and skeletal muscle.”


              “Brown fat is a beneficial type of fat that burns energy and glucose to make heat, and animal studies have shown that it protects against diabetes and obesity. Now, new research suggests long-term exposure to cold environments can stimulate growth of this “good” fat in humans, potentially benefitting glucose and energy metabolism.

  3. Austin

    Todd: quick questions for you. 1) I have a cold/respiratory infection, and a friend of mine thought a cold shower might make things worse. Do you think this claim has merit? I love the cold showers: 1.5 years of them since reading your blog. 2) I also love to run outside in the cold, and I often only wear shorts/a t-shirt; my friend thinks this could somehow cause me health problems if I sweat. Does this have merit? Thanks, Austin. Keep up the awesome work.

    • Todd

      Well, it’s obviously a controversial question. The conventional wisdom is that cold exposure makes us prone to “catching” colds. That’s a partial truth: if your immune system is weakened by unconditioned stresses then, sure, you’ll be more vulnerable to illness. But that totally overlooks the value of cold exposure as a tool to strengthen immunity and acclimate yourself to the cold. My experience is that, for the past 5 or so years I’ve been taking cold showers, I’ve had very few colds (probably two very brief and mild colds lasting a day or two) no flu whatsoever, no sick days. Of course, I couple that with other practices like intermittent fasting and a reduced sugar intake…so it’s hard to single out a single factor.

      I have noticed that people tend to get colds not when they are under stress but AFTER a stressful period when they begin to relax. There is a great book by Marc Shoen about why this happens, called The Letdown Effect. You might find it illuminating.


  4. Great article, thanks. I started taking a cold shower after the sauna and the feeling afterwards is amazing! More recently, there has been a problem with my hot water in my apartment so i needed to use cold water only. The hot water is back on but i prefer to use the cold in the morning because nothing wakes you up like this!

    Cheers for the info, very interesting.

    Mark Kilham

    • donjoe

      Well, since the sauna also produces short-term thermal stress but in the opposite direction, one could expect an alternation of 15-minute sauna sessions and cold showers to enhance the effects of both. Others say that some of the biological mechanisms might cancel eachother out and end up producing no net benefit. I haven’t seen any research attempting to settle this specific question, though there’s pretty good data on the beneficial effects of sauna sessions and cold showers taken separately:

  5. John Hammond

    I have been doing this for about half a year now. There are two questions that have been on my mind for a while though.

    Firstly, do cold showers do a poorer job of cleaning the body of sweat and dirt compared to warmer ones?

    Secondly, can cold showers cause arthritis? It’s a bit of an odd question, but I’ve been told this by some concerned, but very close-minded family members.

    • Todd


      Hot, warm water will clear sweat and dirt faster than cold water, and adding soap or shampoo will also speed up that process. But notice that I said faster, not better. Body soils and sweat are less soluble or dispersible in colder water — so just take a longer shower or use a more intense jet of water to get clean. Also, there is a growing movement of folks who have dispensed with soap and shampoo, and who still get clean in cold water. Part of this has to do with how your hair and skin “adjust” to put out less oil when it is no longer being stripped off as frequently by soaps.

      With cold water, you can afford a longer shower since you are no longer paying to heat the water.

      I have no idea how cold showers could cause arthritis. Perhaps you might feel your arthritic pain more noticeably, but the cold will not by itself cause arthritis, which is inflammatory in nature. If anything, cold water is anti-inflammatory.


  6. An article written five years ago is still getting comments, and you can see why.

    To anyone reading this article, please do what Todd suggests. At least give it a go. The benefits will outweigh any hardships or difficulties you can foresee. Cold Showers used to be a staple of British and Irish boarding schools. Hated by kids, but it toughened them up. My Dad still takes a daily cold shower.

    The only slight divergence for me, would be the use of a plunge pool, instead. I feel the cold shower can sometimes be like taking a bandage off, slowly. With the plunge pool(use a bath, if you don’t have one), it takes a moment of courage and you get all body coverage. The burst of energy…wow, better than an expresso.

  7. Mateusz

    Great article! I take cold showers twice a day and it has great influence on my mood and health. If I use cold showers regularly, I never get sick. I support my cold adaptation also by go outside without warmer clothes (I live in Poland and now temperature is about -5 – 0 C). Thanks to cold showers I can go out unclothed and practically don’t feel the cold. People look at me like I was a freak and they always said that I’ll be sick, I’ll get pneumonia or other serious illness. But it turns out that they get sick, and I’m still healthy.

  8. manuel

    6 minute morning workout before shower

  9. pikachu

    hey 🙂

    i live in switzerland and i have been taking cold showers for a week or so but i find that i dont get that ‘ cold shock ‘ anymore ! i did get those in the first few days but now nothing. and believe me i do the coldest possible setting on my shower and it is around 9 degrees . do the benefits of a cold shower arise mainly and only from the shock factor ? if yes , then im afraid i have nothing to gain anymore . so should i stop or keep going ?

    • Todd

      No – you don’t need the shock to get the benefit! Do you find that you get a warm internal feeling after getting out of the shower? That your mood is improved? That should be enough to stick with the cold showers.


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