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.

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.

Contact thermometers

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.

The pros:

  • Most electronic contact thermometers can record temperatures from the forehead, mouth, armpit or rectum — often in less than one minute.
  • An electronic contact thermometer is appropriate for newborns, infants, children and adults.

The cons:

  • 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.

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.

Remote thermometers

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.

The pros:

  • A remote temporal artery thermometer can record a person's temperature quickly and are easily tolerated.
  • Remote temporal artery thermometers are appropriate for children of any age.

The cons:

  • A temporal artery thermometer may be more expensive than other types of thermometers.
  • This type of thermometer may be less accurate than other types. Direct sunlight, cold temperatures or a sweaty forehead can affect temperature readings. Variations on user technique, such as holding the scanner too far away from the forehead, also may affect accuracy.

Tympanic thermometers

Remote ear thermometers, also called tympanic thermometers, use an infrared ray to measure the temperature inside the ear canal.

The pros:

  • When positioned properly, infrared ear thermometers are quick and generally comfortable for children and adults.
  • Infrared ear thermometers are appropriate for infants older than age 6 months, older children and adults.

The cons:

  • Infrared ear thermometers aren't recommended for newborns.
  • Earwax or a small, curved ear canal can interfere with the accuracy of a temperature taken with an infrared ear thermometer.

Mercury thermometers

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.

Get the latest health information from Mayo Clinic’s experts.

Sign up for free, and stay up to date on research advancements, health tips and current health topics, like COVID-19, plus expertise on managing health.

To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and website usage information with other information we have about you. If you are a Mayo Clinic patient, this could include protected health information. If we combine this information with your protected health information, we will treat all of that information as protected health information and will only use or disclose that information as set forth in our notice of privacy practices. You may opt-out of email communications at any time by clicking on the unsubscribe link in the e-mail.

Nov. 17, 2020 See more In-depth

See also

  1. After COVID-19 vaccination: Is it OK to visit with loved ones?
  2. Alcoholic hepatitis
  3. Can COVID-19 (coronavirus) spread through food, water, surfaces and pets?
  4. COVID-19 and vitamin D
  5. Coronavirus disease 2019 (COVID-19)
  6. COVID-19: How can I protect myself?
  7. Herd immunity and coronavirus
  8. COVID-19 and high blood pressure
  9. COVID-19 and pets
  10. COVID-19 and your mental health
  11. COVID-19, cold, allergies and the flu
  12. COVID-19 (coronavirus) drugs: Are there any that work?
  13. COVID-19 (coronavirus) in babies and children
  14. Long-term effects of COVID-19
  15. COVID-19 (coronavirus) travel advice
  16. How well do face masks protect against coronavirus?
  17. COVID-19 vaccines for kids: What you need to know
  18. COVID-19 vaccines
  19. COVID-19 variant
  20. COVID-19 vs. flu: Similarities and differences
  21. COVID-19: Who's at higher risk of serious symptoms?
  22. Debunking coronavirus myths
  23. Dehydration
  24. Different COVID-19 vaccines
  25. Do you drink enough water?
  26. Excessive sweating
  27. Fever
  28. Fever: First aid
  29. Fever treatment: Quick guide to treating a fever
  30. Flu: When to see a doctor?
  31. Headache
  32. How do COVID-19 antibody tests differ from diagnostic tests?
  33. How does COVID-19 affect people with diabetes?
  34. How to take your temperature
  35. Kawasaki disease
  36. Mayo Clinic Minute: You're washing your hands all wrong
  37. Mayo Clinic Minute: How dirty are common surfaces?
  38. Multisystem inflammatory syndrome in children (MIS-C)
  39. Pregnancy and COVID-19
  40. Coronavirus infection by race
  41. Safe outdoor activities during the COVID-19 pandemic
  42. Safety tips for returning to school during COVID-19
  43. Sex and COVID-19
  44. Teleworking during the coronavirus
  45. Toxoplasmosis
  46. Video: Travel safely for medical care during the COVID-19 pandemic
  47. Treating COVID-19 at home
  48. Unusual symptoms of coronavirus
  49. Fight coronavirus (COVID-19) transmission at home
  50. X-ray