Swimming in cold water what you should know – winter swimrun is around the corner!

This Saturday, the much dreaded Hellas Frostbite Swimrun race takes place. A winter swimrun in Stockholm, Sweden. 

Brrr. It doesnt get much colder than this. But racers, take care. There is much to think of before doing a cold race like this. Check out our guide below. And don’t forget to VOTE for your favourite gear!

/The WoS Team

Today we are interviewing Dr Anders Wallensten on safety issues with swimming in cold water. Dr Wallensten is our dedicated World of Swimrun medical expert.

We know that quite a few of us northerners are keen to jump in the water as soon as the ice clears so that we can get some proper open water swim training. But is it safe?

standard Ram Barkai swims
Ram Barkai founder of the International Ice Swimming Federation swimming in Tyomen lake, Russia, photo Ram Barkai

“If you are in good health and well-trained there should be no problems going swimming in cold water as long as you have proper equipment such as a wetsuit and know what the risks are.”

Good to hear. So what are the risks?

“Well it’s a no brainer really. The risk is primarily getting too cold which may result in hypothermia – abnormally low body temperature. This will eventually happen when you lose more heat than you can generate. You lose heat about 25 times faster in water than in air, so exposure to cold water can quickly lead to hypothermia.”

Why is hypothermia dangerous?

“The human body needs to keep the core temperature relatively stable.  If it drops too low the body will stop functioning and you may even die.

Even mild hypothermia may affect the brain, making the victim unable to think clearly or move well. This makes the condition particularly dangerous because a person may not know what is happening and thus will not be able to do anything about it. This is really bad news during open water swimming as your ability to keep afloat and to orientate yourself may be affected.”

Well, that sounds quite dangerous, so how do we avoid hypothermia if we still want to swim in cold water

“First of all, do not swim alone in cold water. You may need your friend pick up the signs that you are affected. Using a wetsuit will prolong the time you can keep the heat up. In really cold water, leae as little of your skin as possible in direct contact with the water. Knowing the early signs of hypothermia is also very important so you can quit in time or help a friend in trouble as they may not themselves realize they need to get out off the water”

Sounds wise. What are the signs of hypothermia?

“Symptoms vary depending on how low your core body temperature is. But early symptoms are: shivering, fatigue, loss of coordination, confusion and disorientation. If you notice any of these symptoms in yourself or your swimbuddy, get out of the water, get dry clothes on quickly. Drinking warm fluids may help getting warm quicker.

And if you keep swimming despite symptoms?

“Well, that would be really unwise as you risk severe hypothermia which can lead to death. Late symptoms can be that you stop shivering as you are running out of energy, you get blue skin, dilated pupils, slowed pulse and breathing as well as loss of consciousness.”

What do you do if you think someone has hypothermia?

“Mild hypothermia can be treated by getting the person out of the cold water, drying them and putting on dry clothes or wrapping up in blankets. Warm fluids are a good alternative as long as the person can drink.  (Alcohol is not a good choice). Shivering is good as it is the normal body response to raise the body temperature by generating heat from muscle contractions.”

If you think a person had severe hypothermia or you do not manage to warm up a person with mild hypothermia call medical emergency immediately.”

Is there anything you should not do?

“Heating up a person with hypothermia too quickly, for example with hot baths can be dangerous as you may get a severe drop of blood pressure. Rubbing the limbs is also not advised.”

Ok, so do not swim alone, dress for the temperature and know the symptoms and what to do in case of hypothermia, anything else you would like to add?

“Well, maybe that you should be aware of the risk of hypothermia during races as well as training. Although medical teams are at hand you may be likely to take greater risks than you would normally and may therefore not call for help in time. If you of your buddy gets symptoms, make sure to be evaluated by the medical team.

Great, thanks for all the advice Dr Wallensten

“No problem, have fun swimming!”


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