Learn More: Fever
What Is a Fever?
Fever and illness are usually discussed together. An elevated temperature, however, is not always a sign of illness. A fever is merely an abnormal rise in body temperature. Normal body temperature varies throughout the day. Exercise, clothing, stress, and vigorous exercise all cause a rise in body temperature. A fever can also be a symptom of an infection. However, high fever does not necessarily indicate a more serious illness than a mild fever.
Remember that normal body temperature varies from person to person. Although we use 98.6°F as the average body temperature, your "normal" temperature may be slightly higher or lower than that. In general, if your temperature is 100°F or higher, you probably have a fever.
