The body temperature measured by a thermometer inserted into the rectum and retained there for 1 min or more. The usually 1° higher than oral body temperature.
The temperature in the rectum, taken with a rectal thermometer.
The temperature obtained by inserting a thermometer into the anal canal to a depth of at least 1½ in (3.8 cm) and holding it in place for 3 to 5 min. This method should not be used following a rectal operation or if the rectum is diseased. A rectal temperature is more accurate than either oral or axillary temperatures. It averages about 1°F (0.56°C) higher than the oral temperature and approx. 1.5°F (0.84°C) higher than the axillary temperature.