Alan Abrams, age 17, of Staten Island, N.Y., for his question:
WHY DO PEOPLE SWEAT?
Sweat or perspiration is made up of water and certain dissolved substances produced by glands of the skin. The sweat glands are of almost no importance in ridding the body of waste materials but their primary importance is to produce perspiration when the body needs to lose heat.
Sweating itself does not lower body heat but when the sweat evaporates, it has a cooling effect. An inactive person may give off up to one quart of perspiration during a day while an active person may give off as much as 20 quarts.
When the weather is cool, the small amount of sweat that may be produced evaporates almost as soon as it is formed.