Thermometers: Understand the options
Thermometers come in a variety of styles. Understand the different types of thermometers and how to pick the right thermometer for you.
By Mayo Clinic Staff
Choosing the thermometer that's best for your family can be confusing. Here's what you need to know about the most common thermometers.
Regular digital thermometers use electronic heat sensors to record body temperature. These thermometers can be used in the rectum, mouth or armpit.
Armpit temperatures are usually the least accurate. Rectal temperatures provide the best readings for infants, especially those 3 months or younger, as well as children up to age 3. 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 a digital thermometer to take both oral and rectal temperatures, you'll need to get two digital thermometers and label one for oral use and one for rectal use. Don't use the same thermometer in both places.
- Most digital thermometers can record temperatures from the mouth, armpit or rectum — often in a minute or less.
- A digital thermometer is appropriate for newborns, infants, children and adults.
- Parents may worry about causing discomfort when taking a child's temperature rectally.
- You need to wait 15 minutes after eating or drinking to take an oral temperature. Otherwise, the temperature of your food or drink might affect the thermometer reading.
- It can be difficult for children — or anyone who breathes through the mouth — to keep their mouths closed long enough to get an accurate oral reading.
Digital ear thermometers
Digital ear thermometers, also called tympanic thermometers, use an infrared ray to measure the temperature inside the ear canal.
- When positioned properly, digital ear thermometers are quick and generally comfortable for children and adults.
- Digital ear thermometers are appropriate for infants older than age 6 months, older children and adults.
Sept. 12, 2015
- Digital ear thermometers aren't recommended for newborns.
- Earwax or a small, curved ear canal can interfere with the accuracy of a temperature taken with a digital ear thermometer.
See more In-depth
- Ward MA. Fever in infants and children: Pathophysiology and management. http://www.uptodate.com/home. Accessed July 23, 2015.
- Cherry JD, et al, eds. Fever: Pathogenesis and management. In: Feigin and Cherry's Textbook of Pediatric Infectious Diseases. 7th ed. Philadelphia, Pa.: Saunders Elsevier; 2014. http://www.clinicalkey.com. Accessed July 23, 2015.
- El-Radhi AS. Determining fever in children: The search for an ideal thermometer. British Journal of Nursing. 2014;23:91.
- Fever and your child. American Academy of Pediatrics. http://patiented.solutions.aap.org/handout.aspx?gbosid=156451. Accessed July 23, 2015.
- Allegaert A, et al. Tympanic, infrared skin, and temporal artery scan thermometers compared with rectal measurement in children: A real-life assessment. Current Therapeutic Research. 2014;76:34.
- How to take your child's temperature. American Academy of Pediatrics. http://patiented.solutions.aap.org/handout.aspx?gbosid=166297. Accessed July 23, 2015.
- Howells EB. Measuring temperature. Anaesthesia and Intensive Care Medicine. 2015;16:358.
- Thermometers. Environmental Protection Agency. http://www.epa.gov/hg/thermometer-main.html. Accessed July 24, 2015.