A fever is part of the body’s immune response. It's an elevation of body temperature that usually occurs in reaction to an outside intruder, such as a bacteria or virus. The body’s natural temperature (98.6 degrees F) is a good temperature for bacteria and viruses, and the fever is part of the body’s attempt to create an uncomfortable environment for the intruder.
A fever is not a medical condition in and of itself but rather a symptom of an infection or something else that’s wrong in the body. The most common causes of fever are a cold or the flu, but a fever can be related to more serious problems in the body, too. It could be due to strep throat, bronchitis or pneumonia. If someone has been exposed to extreme temperatures or hard work in the heat for long periods of time, a fever could be related to heat exhaustion or heat stroke. It can also be a symptom of serious problems like meningitis, tuberculosis and cancer. In fact, a fever is a symptom of many illnesses so it’s often important to look at the other symptoms when determining the course of action.
Treatment of Fever
If a fever is mild (lower than 101 degrees) and the person has no other alarming symptoms, then treating it with rest, hydration and over-the-counter pain relievers is often sufficient. The exception to this rule is a child younger than 3 months of age, who should be taken to a doctor if the child's temperature goes above 100.4 degrees.
The key thing is to monitor the level of the temperature and other symptoms in order to determine the best course of action. An adult with a consistent fever of 103 degrees or one that rises to 105 degrees should see a doctor right away. Fevers that last 48 to 72 hours or more or fevers, even lower-temperature ones, that come and go for a week or more also warrant a doctor's attention. In a child, a temperature above 104 degrees or a temperature that persists after three days is cause for concern. So are such symptoms as feeling very ill or unusually drowsy. Symptoms like vomiting, diarrhea, sore throat, headache or stiff neck need to be monitored carefully, and a doctor should be called if these persist or increase in severity. Also be wary of any fever that follows heat exposure because this could be a sign of heat exhaustion or heat stroke.
SOURCES:American Academy of Pediatrics; American Academy of Family Physicians; U.S. National Library of Medicine