Fever generated as a response to infection is generally not dangerous. Fever is the body’s natural response to infection. In fact, fever can be thought of as beneficial, since it results in more rapid killing of bacteria and maybe viruses. The cause of the fever may be dangerous, but the fever itself is not. A fever of 105 due to Influenza is mostly a nuisance. A fever of 101 in a patient with bacterial meningitis is quite dangerous and can lead to brain damage. But even in the case of meningitis, the fever is merely a marker for the infection. The meningitis causes damage to the brain, not the fever.
It is important to point out that this discussion of fever is specifically directed towards fevers that are generated internally, by your own body. An elevated body temperature from an external source can be very dangerous, and can cause brain damage or even death. Examples include a child left in a car on a hot day with windows up and no air conditioning, or a football player doing a vigorous workout on a hot day in full pads and uniform. These examples can cause heat stroke, which kills many US children and adults each year.
Fever due to infection does cause people to be more uncomfortable, and most doctors recommend fever lowering medications because it makes the patient feel better. Lowering the temperature with medications like Tylenol or Motrin does nothing to make the infection go away any more rapidly. It just gives temporary relief from the discomfort of fever. Fever from the Flu lasts 4-6 days whether you take Tylenol or not.
The bottom line is that since fever itself does not cause damage to the brain, there is no reason why the fever must be brought down with medications, other than for comfort. This is why doctors do not recommend waking a sleeping child when the next dose of Tylenol for fever is due. If the child is resting comfortably, let her sleep, even if she has a fever.
James Wilde MD, FAAP
Augusta University
Department of Emergency Medicine