Clinical Skills: Body Temperature Assessment

Hello! This video covers how to assess body temperature. Normally you’d do everything on this list, but to keep things concise, this video will focus on the steps in blue and will also cover special populations like infants and the elderly, and include a summary.

Meet Fred. Fred’s deep core temperature is stable, averaging 37.2 degrees Celsius, or 99 degrees Fahrenheit. Fred’s oral temperature is also normal: 37° Celsius, or 98.6° Fahrenheit. 

Fred’s body temperature is where it should be. But what if it weren’t?

Fred might be hyperthermic or feel feverish, depending on the cause of his excess heat. Fever is when the body’s hypothalamic temperature setpoint increases, often caused by infection, inflammation, or malignancy. Hyperthermia is when the body retains too much heat.

A temperature between 37.5 and 38.3°C (or 99.5 and 100.9°F) is classified as hyperthermic. A temperature above 40°C, or 104°F, can be life-threatening.

Or, Fred could be hypothermic. He might have been exposed to cold for a prolonged period of time, accidentally or in preparation for a medical procedure. A temperature below 34.0°C, or 93.2°F, is classified as hypothermic.

Let’s check. We can measure Fred’s temperature in several ways.

Attach the blue, oral probe stem to the thermometer. Slide a disposable cover over the temperature probe.

Ask Fred to open his mouth and insert the thermometer into one of Fred’s posterior sublingual pockets. At the base of his tongue, not in front of it. Ask Fred to keep his lips closed. Wait 20-30 seconds or until the thermometer chimes.

Is Fred comatose, confused, critically ill, or in shock? Is he unable to close his mouth? Use a rectal probe for the most accurate measurement. Roll Fred over and into the Sims position, with the upper leg bent. Wear gloves.

Attach the red, rectal probe stem to the thermometer. Slide over a disposable probe stem cover, and apply plenty of lubricant. With one hand, separate Fred’s buttocks. Ask Fred to breathe slowly. Now, insert the lubricated probe about 3 cm (just over an inch) deep into the direction of the umbilicus. When the thermometer chimes, you can remove the probe and read the temperature.

Fred’s rectal temperature will be 0.4° to 0.5°C (or 0.7° to 1°F) higher than Fred’s oral temperature. This is the most accurate reflection of his core body temperature.

We can also take Fred’s axillary temperature. Attach the blue, oral probe stem to the thermometer. Slide over a disposable probe stem cover.