The primary function of sweating is to regulate body temperature. Sweating is caused by overheating of the body. When we exercise, our muscles are loaded and produce more heat than usual. By excreting sweat on the surface of the skin, the body tries to get rid of excess heat or cool down. Sweat evaporates from the surface of the body and thus cools it. Sweating is simply the production and excretion of body fluid. Sweat is made up of water, salt and electrolytes and is mostly odorless. The process of sweating takes place all the time, but because the amounts of secretions are so small, we do not notice it at all: we notice it when, due to increased cooling needs, the amounts of excreted sweat increase and begin to stay on the skin, hair or hair.