The Importance of Fevers

"A fever is an increase in body temperature above the “normal range.” But the definition of “normal” can vary from person to person. Body temperature also varies with different levels of activity and at different times of the day. Medical texts differ in their definition of the highest “normal” body temperature, which can range from 98.6 to 100.4°F. It is generally accepted that a fever is defined as an “early morning temperature greater than 99°F or a temperature greater than 100°F at any time of the day.
There are several causes of fever, but it is most commonly associated with dozens of different viruses, bacteria and parasites that cause upper respiratory infections, pneumonia, diarrhea, and urinary tract infections.

When infectious micro-organisms invade the body, it is fever that gets our attention. Yet, despite its universal recognition, little is known about how is occurs. The currently held view is that when an infectant enters the body, the body activates its innate immune responses, which include the release of a complex mediators with equally complex names: cytokines, pyrogenic molecules that including tumor necrosis factor alpha (TNFα), interleukin (IL-1β) and interleukin (IL-6). These substances signal the part of the brain called the hypothalamus to raise the body’s thermostat, which in turn leads to chills and shivering to increase the metabolic rate. Heat loss is minimized by restricting blood flow to the skin, giving it a pale appearance. Fever sufferers may lose their appetite and most feel lethargic, achy, and tired.

However, contrary to the reflex need to give an aspirin to make a fever stop, an elevated temperature can be an expression of the immune system working at its best. The number of white blood cells is increased and cascades of molecules to flood the blood stream, in rapid pursuit of the host’s invaders. Fever impairs the ability of bacteria and viruses to replicate, creating an inhospitable environment for the invading organisms. By turning up the heat, invading microbes cannot replicate and by definition, die off. Fever results in winning the war against a wayward microbe..."  

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