Thermometers come in a variety of shapes and sizes. Some are more accurate than others and each have their own pros and cons.

The most commonly used thermometer in the home is the digital thermometer.

Digital thermometers can be used to record temperatures from the mouth, armpit or rectum. Armpit temperatures are the least accurate.

Rectal temperatures provide the most accurate readings for children between 3 months and 3 years of age. However, taking a temperature rectally can cause worry for the parents and discomfort for the child.

Oral temperatures are not as accurate as rectal temperatures, but they are certainly more convenient.

To record a temperature orally using a digital thermometer:

  1. Reset the thermometer by pressing reset button
  2. Place the thermometer under the tongue
  3. Close mouth around thermometer
  4. Leave in place until you hear the beep (usually one minute or less)
  5. Read the level shown on the digital display
  6. Clean the thermometer by wiping with anti-septic or luke-warm water

If using thermometers for both oral and rectal temperature recordings, use two different, clearly labelled thermometers for obvious reasons!

Get rid of your mercury thermometers; they are no longer recommended as the glass can break, and the mercury inside is toxic.

Other thermometers not commonly used in the home, in order of accuracy are temporal artery thermometer, the ear (tympanic) thermometer and fever strip thermometers.

Always follow manufacturers’ instructions to get the most accurate results.

Last Reviewed: 24/07/2019

myDr