Elina Mäkinen, a fan of traditional "avanto" swimming - in holes dug in the ice - is preparing for the Ice Mile, a swimming event organized in the Norwegian archipelago of Svalbard, where the water temperature is around 0°C. How does the young woman resist these extreme conditions? What effects does the cold have on the body? Beyond the risk of frostbite, hypothermia alters the cardiovascular system, even causing death when the internal temperature drops below 25°C. Different factors such as age, fatigue, dehydration or disease can accelerate body cooling.