The temperature of the body is controlled by a section of the brain that acts like a "thermostat". Fever results when the body's thermostat is reset higher. Body temperature can "reset" for any number of reasons. If the temperature is set higher, the body feels cold and may send out a signal to the muscles. The muscles begin to shake repeatedly. This involuntary shaking, or chills, makes body heat that helps produce fever. Chills can be constant for up to one hour, or they can come and go. Fever is a helpful response to infection.

Oral thermometer readings for fever are:
* Low: 99 to 101.4 F. or 37.2 to 38 C.
* Moderate: 100.5 to 104 F. or 38 to 40 C.
* High: above 104 F. or above 40 C.

Medical questions need to be asked for low and moderate fevers. This helps to uncover other signs and symptoms. Fever by itself is not very useful in pinpointing a cause. Keep a temperature log. Record:
* When did the fever begin?
* What was the highest reading?
* Is it constant, or did it go away and come back?
* Is the person feeling any pain, tiredness, or chills?
* Has the person recently been sick or injured?
* Is the person taking any drugs?
* Has the person recently had medical tests or surgery?

Seek medical evaluation if fever is accompanied by any other major symptoms, such as:
* An altered mental state.
* A rigid neck.
* Trouble breathing.
* No production of urine.
* Forceful vomiting.
* Complaints of moderate to severe pain.
* Redness, pain or other sign of infection on the body.

Acetaminophen or aspirin may be given to kids above age 12 and to adults. Acetaminophen may be given to children. Check with your pharmacist or the drug label for the correct dose. Any fever that lasts longer than 3 days or fever above 106 F. (41.1 C.) requires medical attention.

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