Humans are warm-blooded animals. If they gets too hot, they can tune down their body temperature. This feat is achieved by an evolutionarily refined "AC system" in the skin: the sweat glands. However, evolution did not yet know anything about winter sports, and so our heat balance is thrown into a spin if we want to protect ourselves from the freezing cold while skiing and at the same time sweat unhindered. New tech has been designed to keep athletes warm and dry – thanks to “electrical” textiles.