Normal sweating is the body's way of controlling its temperature, by keeping body temperature at a constant level. When the body's temperature is elevated, or above normal, the body's sweat glands work to lower body temperature by increasing body perspiration. Sweat glands produce moisture on the surface of the skin. As the moisture evaporates, the skin is cooled, decreasing the temperature of the body. The body normally loses over a pint of perspiration each day.
Sensible perspiration occurs when the body sweats more than the normal amount.
Examples of sensible perspiration include the body's response to hot weather temperatures, strenuous exercise, times of emotional stress, and when an illness has caused a fever. Under these circumstances, the body's perspiration can be more than several quarts in a day as the body works to lower its temperature by increasing the amount of moisture produced by sweating. Night sweats are defined as excessive, or profuse, sweating that occurs during the night. This sweating is so extreme that bed clothes will frequently need to be changed. Night sweats can have many varied causes.