Nurses are Masters at the Fine Art of Caring

Taking Vital Signs: Temperature
©2006-Present By Kathy Quan RN BSN
All Rights Reserved
This article first appeared on in 2006

Each time you visit your health care provider, someone takes your vital signs and usually weighs you. What do vital signs tell about your condition?
If you are healthy or stable you might look over your medical chart and see that the numbers become monotonous. However, if you are ill, or any chronic condition is unstable, your numbers might vary widely.
The 5 Vital Signs
Vital signs consist of Temperature, Pulse, Respirations, and Blood Pressure. Over the past few years a fifth vital sign has also been added to the loop...Pain.
Temperature - What's Normal?
Body temperature for an adult is said to be normal at 98.6 degrees F (37 degrees C). However, it is quite normal for body temperature to vary by one or two degrees (97.5 to 99.5 degrees F or 36-38 degrees C). Some people run sub normal and some run a degree higher. Body temperature will also vary with the time of day. It can be lower in the morning and slightly higher in the late afternoon or evening.
Influencing Factors
Temperature can be influenced by other factors such as exercise or a lot of activity prior to checking the temperature. Drinking cold or hot liquids can also affect an oral temperature. Of course the accuracy of the thermometer can also affect the results.
Types of Thermometers
There are several types of thermometers. These include glass or digital thermometers. An oral thermometer is used by placing it under the tongue for an oral temperature; or into the armpit for an axillary temperature. A rectal thermometer is primarily used for infants and small children. The tip of the rectal thermometer is placed (carefully) into the rectum. An ear thermometer takes a tympanic temperature.
How Long Does It Take?
When taking an oral, axillary or rectal temperature with a glass thermometer use caution so as not to break it. It should be held in place at the tip for three minutes. Digital thermometers record much faster and need to be help in place only until they beep. The tympanic thermometers usually take only seconds to record and can be safely used on infants and small children as well as adults.
How Will the Site Affect the Temperature?
An axillary temperature will typically read one-half to one degree lower than an oral temperature and a rectal temperature will typically read a degree higher than an oral temperature. The tympanic temperature is usually the same as an oral temperature, and considered to be more accurate as there are fewer influencing factors.
Fever VS Hypothermia
An elevated temperature is known as a fever or hyperthermia and a low body temperature is referred to as hypothermia. Unless otherwise directed by your own health care provider, temperatures greater than 101 degrees F or lower than 96 degrees F (greater than 38 degrees C and lower than 36 degrees C)need immediate intervention; call your health care provider or seek medical care. Children can tolerate higher temperatures than adults, but check with your pediatrician for parameters to report.
What Can it Mean?
An elevated temperature can be due to such factors as infection, hyperglycemia (high blood sugar) or DKA (diabetic ketoacidosis). Hypothermia can result from such factors as hypoglycemia (low blood sugar), hypovolemia from blood loss, anemia, and narcotic use. See your health care provider for further assessment and diagnosis.