Fever could be defined as the regulation and control of body temperature. It is the body’s natural reaction to external infection. The absence of it could well be a pointer to some serious illness. The human body has an extremely narrow range of temperature regulation. It is absolutely essential for the proper functioning of the enzymes. Despite variations in temperature around the body, it maintains the delicate balance. It is usually accompanied by sweating and chills.

Heat is generally produced by the action of the thyroid hormones, and muscles play an important role in it. The constant body temperature is, however, maintained by nervous regulation at the hypothalamus.

Normal Range
In healthy individuals, the body temperature is somewhere between 36.5°c and 37.5°c. It increases marginally during the day. The lowest temperature is between 2:00 a.m. and 4:00 a.m.

The term “fever” is used when the body temperature increases above 37°c. Shivering, chills and vasoconstriction in the skin are seen. The body temperature is increased by decreasing the loss of heat. At the same time, the production of heat in the organism increases. Muscle tone increases and spasms may occur.

Fever could be the outcome of a number of stimuli such as bacteria and their endotoxins, viruses, yeasts, spirochetes, protozoa, immune reactions, several hormones, and even some medications.