homeostasis
The tennis player in Figure below has really worked up a sweat. Do you know why we sweat? Sweating helps to keep us cool. When sweat evaporates from the skin, it uses up some of the bodys heat energy. Sweating is one of the ways that the body maintains a stable internal environment. It helps keep the bodys internal temperature constant. When the bodys internal environment is stable, the condition is called homeostasis .