For those who have the care of the sick, heat regulation is a matter of very great importance, because it has to do with the care of the fever patient. The temperature of the body can rise above the normal, either through an increased heat formation (thermogenesis) or through a decreased heat loss (thermolysis). Body temperature, then, is governed absolutely by the interaction of these two factors, thermogenesis increasing it and thermolysis decreasing it. Anything which increases thermogenesis raises the temperature until that is adjusted by a corresponding increase of thermolysis. Anything which increases thermolysis decreases the temperature until that is adjusted by an increased thermogenesis. In order to maintain an even temperature these two factors of body heat, thermogenesis and thermolysis, must increase and decrease together. A change of one must be followed by a change of the other in the same direction, or the body temperature will become subnormal or above normal as the case may be. Temperature above normal, if considerable and maintained for an appreciable length of time, is called fever,

From time immemorial, those who have had the care of the sick have recognized fever as one of the most important symptoms of sickness, and have attempted to control it by various methods.

From the standpoint of the dietitian heat generation may be increased by the ingestion of solid foods that require considerable activity on the part of the glands of the digestive system. As a rule, then, the first step in the dietetic control of fever should be to decrease foods to the minimum of the body's requirement and present these foods in the condition most easily digested and assimilated.

Further, certain foods and beverages, particularly the latter, possess a diuretic and diaphoretic action. The free ingestion of these foods, which increase skin and kidney action, tends to lower body temperature through increasing the thermolysis.