Fever
A fever is when a person's body temperature is hotter than 37.5 degrees Celsius (99.5 Fahrenheit). Normal body temperature for humans varies based on a variety of factors, including age and level of physical activity.  It is typically cited as 37 degrees Celsius (98.6 F), but naturally varies from person to person by at least .5 degrees Celsius. The actual measurement of body temperature will vary based on the location of the measurement.  For a temperature taken from under the tongue, the measurement may be lower. Rectal temperatures will read about 0.3 C (0.55 F) higher, and armpit temperatures will read about the same amount lower.