What type of thermometer should I use?
There are 4 ways to accurately take (measure) a temperature:
- Under the armpit (axillary method)
- In the mouth (oral method)
- In the ear (tympanic method)
- In the rectum (rectal method)
A digital thermometer is best for taking temperatures by the armpit and mouth.
Fever strips and pacifier thermometers do not give an accurate temperature. Do not use a mercury thermometer. Mercury is toxic and the thermometer could break.
Speak to a pharmacist/health care provider if you have any questions when buying a thermometer.
Whichever type of thermometer you use (except ear thermometers), clean it with cool, soapy water and rinse off before and after use.
Axillary method (under the armpit)
The armpit method is usually used to check for fever in newborns and young children:
- Place the tip of the thermometer in the centre of the armpit
- Tuck your child’s arm snugly (closely) against their body
- Leave the thermometer in place for about one minute, until you hear the “beep”
- Remove the thermometer and read the temperature
Oral method (in the mouth)
The mouth method can be used for children who are older than 5 years of age. It is not recommended for children younger than 5 years of age, because it is hard for them to hold the thermometer under their tongue long enough:
- Carefully place the tip of the thermometer under your child’s tongue, off to the side, and at the base of the tongue
- With your child’s mouth closed, leave the thermometer in place for about one minute until you hear the “beep”
- Remove the thermometer and read the temperature
Tympanic method (in the ear)
The ear method is recommended for children older than 2 years old.
Though quick to use, the ear method can be inaccurate even when the manufacturer’s directions are followed:
- Use a clean probe tip each time, and follow the manufacturer’s instructions carefully
- Use a clean probe tip each time, and follow the manufacturer’s instructions carefully
- Squeeze and hold down the button for one second
- Remove the thermometer and read the temperature
Rectal method (in the rectum or bum)
The rectal method can be used to check for fevers in newborns and young children. Use a rectal thermometer only if you are comfortable doing so and a health care provider has shown you how to do it safely:
- Cover the silver tip with petroleum jelly (such as Vaseline)
- Place your baby on their back with their knees bent
- Gently insert the thermometer in the rectum, about 2.5 cm (1 inch), holding it in place with your fingers
- Leave the thermometer in place for about one minute until you hear the “beep”
- Remove the thermometer and read the temperature
For more detailed instructions on how to take a temperature using the rectal method, speak to your health care provider.
After a thermometer has been used to take a rectal temperature, do not use it to take an oral temperature. Make sure that the rectal thermometer is clearly marked so that it is not used orally. For example, you could label your rectal thermometer with an “R” and your oral thermometer with an “O”.
Over the forehead (temporal artery method)
Non-contact infrared thermometers (NCITs) may be less accurate than other thermometers such as oral, rectal or well-calibrated tympanic thermometers. Several factors influence the ability of NCITs to accurately detect fever, including:
- Relative humidity
- Significant perspiration
- Positioning on forehead
- Exposure to cold or hot weather before temperature measurement
Follow best practices and the manufacturer's instructions when using NCITs. NCIT readings do not themselves rule in or rule out the presence of a fever. NCITs are not the recommended temperature taking method for children.
How should I take a child’s temperature?
From birth to age 5, the most common way to take a temperature is under the armpit. For children older than 2, temperatures can also be taken by ear or, if the child is able to sit still long enough, by mouth (not recommended for children under age 5). The most accurate way to take a temperature is in the bum (rectal method). See the section on the rectal method to learn how to safely take a rectal temperature.
Always wash your hands before and after taking your child’s temperature. For more information on hand washing, visit HealthLinkBC File #85 Hand washing: Help stop the spread of germs
What can I do if my child has a fever?
