The normal temperature varies by person, age, time of day, and where on the body the temperature was taken. The average normal body temperature is 98.6°F (37°C).

Your body temperature is usually highest in the evening. It can be raised by physical activity, strong emotion, eating, heavy clothing, medications, high room temperature, and high humidity.

Daily variations change as children get older:

• In children younger than 6 months of age, the daily variation is small.
• In children 6 months to 2 years old, the daily variation is about 1 degree.
• By age 6, daily variations gradually increase to 2 degrees per day.
• Body temperature varies less in adults. However, a woman's menstrual cycle can raise temperature by one degree or more.

For information on when to call a doctor due to specific temperatures and ages, see the article on fever.

If the reading on the thermometer is more than 1 to 1.5 degrees above the patient's normal temperature, the patient has a fever. Most fevers are a sign of infection and occur with other symptoms. Abnormally high or low temperatures can be serious, and you should consult a health care provider.