Perspiration, or sweating, is a natural process that helps regulate body temperature. It is caused by the release of water and salt from the sweat glands in the skin. Perspiring, or sweating, is the body's way of cooling itself down when it gets too hot. Sweating is an important part of the body's natural cooling system, and it helps to keep the body at a comfortable temperature. Perspiring is also a sign of physical exertion, such as during exercise or when feeling anxious.