Thermometers come in a variety of styles. Understand the different types of thermometers and how to pick the right thermometer for you.
Types of thermometers
In general, there are two types of thermometers. Touch, or contact, thermometers must touch the body in order to measure temperature. Remote, or no contact, thermometers can measure body temperature without touching the skin.
The most common kind of contact thermometer uses electronic heat sensors to record body temperature. These thermometers can be used on the forehead, mouth, armpit or rectum. Most electronic thermometers have a digital display that shows you the temperature reading.
Rectal temperatures provide the most-accurate readings for infants, especially those 3 months or younger, as well as children up to age 3. Temperatures taken from the armpit are usually the least accurate. For older children and adults, oral readings are usually accurate — as long as the mouth is closed while the thermometer is in place.
If you plan to use an electronic contact thermometer to take both oral and rectal temperatures, get two thermometers and label one for oral use and one for rectal use. Don’t use the same thermometer in both places.
Many schools, businesses and health care settings are screening visitors for fever. A remote thermometer that doesn’t require skin contact allows people to remain further apart. Remote thermometers can be used on the forehead (temporal artery) or the ear (tympanic).
Temporal artery thermometers
Remote forehead thermometers use an infrared scanner to measure the temperature of the temporal artery in the forehead.
Remote ear thermometers, also called tympanic thermometers, use an infrared ray to measure the temperature inside the ear canal.
Once a staple in most medicine cabinets, mercury thermometers use mercury encased in glass to measure body temperature. Mercury thermometers are no longer recommended because they can break and allow mercury — which is toxic — to escape.
If you have a mercury thermometer, don’t throw it in the trash. Contact your local trash collection program to see if there’s a hazardous waste collection site in your area.