What causes a fever?

A fever has many causes and can be a symptom of almost any illness. Among the most common are:

However, if you or a loved one are experiencing a higher-than-normal body temperature and no other symptoms of illness, do not assume something is wrong. A person's body temperature changes throughout the day and varies with many normal activities and emotions. For example, stress, excitement, wearing extra clothing, food, certain medications, a woman's menstrual cycle and exercise can all raise body temperature. Also, children tend to have a slightly higher body temperature than adults.

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