Body temperature readings vary depending on where on the body a person takes the measurements. Rectal readings are higher than oral.
Scand J Caring Sci. 2002 Jun;16(2):122-8. Normal oral, rectal, tympanic and axillary body temperature in adult men and women: a systematic literature review .
Most people think a normal body temperature is an oral temperature (by mouth) of In most adults, a fever starts at an oral or axillary temperature of 37.6°C (99.7 °F) A child has a fever when his or her rectal temperature is 38°C (100.4°F) or.