Adaptation to cold and winter swimming

Since I’ve seen a Dutch news report on Siberian winters last Friday I have been fascinated by how some (or many?) people in cold environments can adapt to very low temperatures. In the news report they cover ice fishing on the Ob river near Barnaul. Let me translate it for those who don’t know Dutch.

Reporter: it is -27 ℃, the ice one and half meters thick. But the Siberians here don’t think it’s cold at all, it is ‘just’ -27 ℃, they say.

Siberian: what do you mean, cold? I don’t even have my jacket on. Are you making a joke? It is warm today, it’s not cold at all! We think it’s cold when it’s -42 ℃, -25 ℃ is warm and if it’s -15 ℃ it is so warm that it isn’t interesting to come any more. Then it’s like summer.

Reporter: tents provide some protection against the cold, but seasoned Siberians like Aleksandr don’t even need those.

Aleksandr: why would I need a tent? The sun shines! Today it’s extremely hot, it’s beautiful, it’s a delight to sit here.

Both Siberians which are interviewed are ice fishing without any gloves on, with their bare hands. The comment about -27 ℃ being extremely hot seems like hyperbole to me, because the average high for Barnaul in July is 26,2 ℃ according to Wikipedia. But they’re not bragging if they have no qualms about exposing their bare hands in that low temperature. The Wikipedia article on frostbite mentions that some individuals and population groups are more resistant to frostbite because of their adaptation and exposure to very cold environments. Curious as I was, I decided to fire up Google Scholar to learn more.

A more recent article by Daanen (2003) which is cited often gives a review on cold-induced vasodilation (CIVD). I noticed this term doesn’t have an article on Wikipedia yet so I hope to write one in the near future myself. When the finger tips are exposed to cold CIVD usually occurs after five or ten minutes and is believed to reduce the risk of injuries from cold exposure. People who are often exposed to local cold such as fish filleters develop an increased CIVD response with an earlier onset, and race (along with many other factors) also plays a role with black people having the weakest CIVD response. Further on in the article adaptation and acclimatisation are elaborated on, with a large table showing the large differences in CIVD obtained from many prior experiments.

However, the notion that black people would have an inherently inferior CIVD response as the introduction of the article seems to indicate is put into perspective at that point. One experiment showed that tropical residents who lived in an Arctic region for seven weeks acclimatized and showed the same CIVD response as the Arctic natives. Caucasians had a lower CIVD response than Japanese, but when the Japanese were compared with Caucasians living in the same region in Japan there was no difference. Therefore the conclusion is that ambient factors such as acclimatisation and diet may be more important than ethnic differences. The article concludes that while it is difficult to distinguish between the effect of adaptation and acclimatisation, people born in cold regions and people who expose their hands to cold for a prolonged period of time have an increased CIVD response.

We had some very cold weather in the Netherlands for the last weeks, see this graph with the grey line showing the normal average temperature for February and the blue and red line showing minimum and maximum temperature respectively. After witnessing the Siberians on the news I thought I should be able to handle the cold without gloves too, but it was not an easy ordeal. Let’s take last Monday for example, February the 6th. According to the graph the minimum temperature was -15 ℃ and the maximum -3 ℃. That day started with me going to the bus stop. Without gloves my hands felt cold and painful initially but after approximately ten minutes the pain went away and I regained the sensation in my fingers. However, later I had to wait at Utrecht Central Station and Rotterdam Central Station for delayed trains. As such, after my hands had warmed up in the bus they had to cool down again two times. These subsequent periods were much more painful for my hands and my CIVD response seemed to take a lot longer to kick in.

It seems like I still have a long way to go until I can compete with the Siberians, and right now it looks we’re going to see warmer weather in the Netherlands for the rest of the winter, without temperatures below freezing during the day. Not that I expected that increasing my acclimatisation would be easy. But even if the freezing temperatures are going away, there still is another solution, winter swimming.

Yesterday I watched the short documentary The Ice Tribe on YouTube, which shows ordinary Finnish people enjoying ice swimming. That’s winter swimming in a hole in the ice, in this case with a water temperature of 0 ℃. There are more video’s on YouTube showing this, for example a Estonian women even dives under the ice without too much discomfort. These persons do seem to have some experience which enables them to endure the cold water for at least one minute, because other videos show inexperienced people quickly leaving the water within ten seconds. And I was thinking only supernatural persons like our Wim Hof, the Dutch Iceman, could pull off feats like that.

What is notable is that the ice swimmers in the documentary describe ice swimming as a great experience. Some scientific research has been done on the benefits of winter swimming, with the consensus being that it indeed provides physical and psychological benefits. In their introduction Siems, Brenke, Sommerburg and Grune (1999) argue that we have effectively become weaklings thanks to our modern Western society because we protect ourselves so well from cold and heat stresses with heating and air conditioning. This sounds very familiar to me, with my sister and brother who are eager to turn up the heating to 21 ℃ with the recent cold temperatures here.

This absence of cold and heat stress is suggested to have led to a greater incidence of disease. These negative consequences can be partly prevented by exercise and body hardening, with cold exposure being a traditional example of hardening. They report that previous studies have revealed that winter swimmers contract infectious diseases much less often. They researched experienced winter swimmers who swim at least once per week in ice-cold water for about five, but not more than ten, minutes. Their research concludes that winter swimmers have a better defence system against oxidative stress than the Average Joe. Similarly, Huttunen, Kokko and Ylijukur (2004) also conclude from their experiment that winter swimming significantly improves general well-being.

So, if both anecdotal and scientific evidence says it’s good I want to start doing it too. There are several large bodies of water in my neighbourhood which are suitable for swimming, but I think it’s too much trouble to make a short trip to go winter swimming. I could fill the hot tub in the garden without heating it up, but this is also troublesome for me because a hot tub needs a lot of water before it’s filled and it needs to be cleaned because it’s exposed outside. What seems like a better idea to me are cold showers. This alternative is easy, saves water and saves gas for heating. With the current temperatures I like standing in the shower for a long time with very warm water. Today I’ve taken a shower with lukewarm water without any discomfort, and plan to lower the temperature each time for successive showers until the water doesn’t get heated at all. Unheated water from a water pipe is probably not 0 ℃ even in the winter here, but it should do. Maybe I’ll switch to hot water for a minute to finish off, but from now on I’ll be taking ‘winter’ showers and doing myself, my father’s wallet and the environment a favour.


Daanen, H.A.M. (2003). Finger cold-induced vasodilation: A reviewEuropean Journal of Applied Physiology, 89(5), 411–426.
Huttunen, P., L. Kokko and V. Ylijukur (2004). Winter swimming improves general well-being. International Journal of Circumpolar Health, 63(2), 140–144.
Siems, W.G., R. Brenke, O. Sommerburg and T. Grune (1999). Improved antioxidative protection in winter swimmers. QJM: An International Journal of Medicine, 92(4), 193–198.

3 thoughts on “Adaptation to cold and winter swimming”

  1. Goodness and Grit

    I am an ice swimmer in Norway. Once a week a group of crazy ladies and I swim in a local canal early in the mornng. We have so much fun, giggle like school girls, and swear it not only helps the immune system, it decreases cellulite, and makes really cold days feel much less cold. Find a group and join the crazy!

    Klem (hugs in Norwegian)

  2. Thanks for your comment Kimberly. You remind me that I still need to follow up on my own plan to take a dive in a lake nearby now that summer has passed. You have a nice blog by the way!

  3. Pingback: First New Year’s dive ever | Information Overload

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