Extreme cold adaptation in humans, part 2

Part 1 of Extreme Cold Adaptation in Humans.

Let’s back up a bit. Way back in fact, to some of my first posts, where I talked about Habituation and Acclimatization.

By the way, if I was writing those posts now, since my experience had changed again, I would have different figures. It’s good that I can still see progression from there, because for those of you who are maybe further behind on the curve, or further ahead, we can all be assured that we are on the same relative learning curve.

For a quick recap, habituation is the learned process (for our purposes) of getting used to getting into cold water.

Habituation doesn’t necessarily mean you get better at it (though it is fairly inevitable). It just means you get more used to doing it (not quite semantic difference). So you know that it’s not really going to kill you, and the pain is transient, therefore you don’t have to fight yourself quite as much to go or to get in the water.

Acclimatisation is the process of becoming used to and better at, staying in cold water. Therefore they are two quite separate processes. (It’s not acclimation by the way, since it happens in the natural environment.)

One can also see back those posts I was asking “how can Thought affect your cooling rate?”, which is your ability in cold water. I obviously used a capitalised word to indicate directed mentation toward the specific end of extending time spent swimming.

Over the past year and half I’ve indicated all (I think) of the pertinent environmental and physiological contributors.

So let’s set most of those aside (weather, health, diet).

Swimmers call the process of getting better at cold water hardening. Here’s some experiental data from swimmers about the hardening process: You can lose it four to five times quicker than you gain it. Sorry to start at the end but it’s because we can at least quantify it a bit better.

Going back to the start though, and what I tell people who ask me, is that you see a definite improvement in your short-term in-water experience within about five swims, in any particular lower temperature range. So if you start at 12 C, you will see the improvement there, whereas someone who starts at 10C should see a similar improvement.

Some people I’ve talked to starting off, separate from the not-insignificant initial problem of just immersing the face, found it difficult to impossible to hold their face in the water for more than four or five minutes, in what I would consider warmish water (12C). Others found pain in the hands and/or feet to be the issues, some find the desperate gasping for air to be the worst aspect. Some have many or all of these symptoms to varying degrees.

In fact, writing it all down like that makes you wonder why on earth we would ever voluntarily subject ourselves to it?

Also, a reminder, don’t look at someone heavier and assume it’s easier for them, a common mistake. A heavier person has greater volume so retains heat longer, but the initial pain will be just as intense.

So, we levelled the field and we’re back to the initial question: take me and someone else approximately similar measurements, standing on the Guillamenes platform in mid February about to get into the water. And assuming I have more experience I will be out later. Why?

I had not planned to leave you hanging here, it just turns out that as I write this, in this format, it is taking more than I initially realised, that I can pull in others factors to do a more comprehensive essay on the subject.


Go to Part Three of Extreme Cold Adaptation in Humans.



9 thoughts on “Extreme cold adaptation in humans, part 2

  1. Pingback: Extreme cold adaptation in humans, part 1. | LoneSwimmer

  2. Hi
    Love the site and the pasion. Learnt loads. I’ve been open water swimming in the UK since April 17 (now 17 Dec). The lakes are 3°c now and I swim 20mins (about 1km) weekly. I’ve noticed tingling in my finger tips lasting a few days. It’s nothing debilitating, but I wonder if I’m in danger of doing any permanent nerve damage. Any advice from your knowledge / experience please? Many thanks, Andrew


    • Hi Andrew, Apologies for the delay replying. I actually did really want to get back to you because it’s an important question, and I’ve wanted to write a longer article about it which I’m still planning. In brief, yes, there is a possibility of permanent damage. It’s called in general a Non-freezing cold injury, which can for some people result in very long lasting (up to 2 years) or even permanent nerve damage. It is the least discussed aspect of extreme cold water swimming, and the one that I most despise the International Ice Swimming Association for not being clear about. Some swimmers I know have actually hidden their symptoms, and I know expert cold water swimmers who have developed these problems after years of successful cold water swimming. The risk arises once the temperature drops below 5C and the swim time extends.

      I don’t want to be alarmist, that’s not what this blog is about, but this is a real problem. I would advice decreasing your time or not swim other than an short dip once the water is below 5C.

      I hope this helps. Sorry to be the bearer of bad news. Best wishes.


      • That is very interesting and extremely helpful to know. Thanks indeed for coming back with such a comprehensive answer. Much appreciated!


  3. Pingback: Adaptation to cold: habituation and acclimatization | wildbigswim

  4. So, what do you actually do to start habituation and aclimatisation before actually getting in the cold open water? Is there a step which you suggest prior to that that is helpful? Would sitting in a bathtub filled only with cold water for longer periods of time each time be a good starting point? Or is this process you just dive right into by getting into the open water?


    • Hi Michael, The usual advice given to people intending something like a Channel swim is to first get used to having cold showers. (I admit to never doing that). It certainly does work though. Ice filled baths seems like too much hardship to me, I’d prefer to swim and simply extend the swim time gradually. Capability only builds up over a period anyway.


      • Thank you for your response regarding my question. I asked my question because I tried “taking the plunge” by just getting in the cold water twice, trying to do what you speak of in your articles. I tried telling myself that I can get past that initial shock, and that I will be okay once I get moving. Yet the stinging from the cold causes me to get out of the water after a few strokes. I do not want that flight turn into a permanent fear, so I thought there would be a way to acclimate before heading back into the open water. I will try the cold shower and see what happens, then get back with you in the near future.


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