What is a normal body temperature?

A normal body temperature when measured orally is around 98.6 degrees Fahrenheit, according to WebMD. It is normal for body temperature to fluctuate as much as one degree above or below 98.6 degrees throughout the day.

WebMD further explains that normal body temperature fluctuates in response to the time of day, the activity level of the person and other factors, such as hormone levels. The most accurate way to measure body temperature is rectally. Rectal temperatures are normally slightly higher than oral temperatures. An oral temperature above 100.4 degrees or a rectal temperature above 101.4 degrees is classified as a fever.