Fever
Diagnosis
Temperature in the anus (rectum/rectal) is at or over 37.5–38.3 °C (99.5–100.9 °F) An ear (tympanic) or forehead (temporal) temperature may also be used. Temperature in the mouth (oral) is at or over 37.2 °C (99.0 °F) in the morning or over 37.7 °C (99.9 °F) in the afternoon Temperature under the arm (axillary) is at or over 37.2 °C (99.0 °F) In adults, the normal range of oral temperatures in healthy individuals is 33.2–38.2 °C (91.8–100.8 °F), while when taken rectally it is 34.4–37.8 °C (93.9–100.0 °F), for ear measurement it is 35.4–37.8 °C (95.7–100.0 °F), and for armpit (axillary) measurement it is 35.5–37.0 °C (95.9–98.6 °F). Harrison's Principles of Internal Medicine defines a fever as a morning oral temperature of >37.2 °C (>98.9 °F) or an afternoon oral temperature of >37.7 °C (>99.9 °F) although normal daily temperature variation has been described as 0.5 °C (0.9 °F).[verification needed] Normal body temperatures vary depending on many factors, including age, sex, time of day, ambient temperature, activity level, and more. A raised temperature is not always a fever; for example, the temperature of a healthy person rises when he or she exercises, but this is not considered a fever, as the set point is normal.[citation needed] On the other hand, a "normal" temperature may be a fever, if it is unusually high for that person; for example, medically frail elderly people have a decreased ability to generate body heat, so a "normal" temperature of 37.3 °C (99.1 °F) may represent a clinically significant fever.
Fever-7