A closer look
Pouring ice water over your head is an incredibly inefficient way to cool down. Stanford biologists discovered that mammalian palms, soles, and faces contain specialized blood vessel networks called AVAs that act as the body's natural radiators. By placing a mildly cold, vacuum-sealed glove on the hand, they found they could rapidly pull heat out of the circulating blood, dropping core body temperatures drastically faster than full-body ice baths. This thermal exchange technology is now used by NFL players and military personnel to prevent catastrophic heatstroke in extreme environments.
