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When your child is sick with an infection (caused by either bacteria or a virus), it is normal to have a fever. A fever will not hurt your child. Usually, it goes away after 72 hours (3 days).
Babies younger than 6 months old should see a doctor when they have a fever. Older children can be treated at home, as long as they get enough liquids and seem well otherwise.
There are several ways to take your child’s temperature:
rectal method (by the rectum or ‘bum’);
oral method (through the mouth);
axillary method (under the armpit); and
tympanic method (in the ear).
The right method depends on your child’s age. And it’s important that the measurement is accurate. For instance, taking a rectal temperature is the best way to get an exact reading for children under 2 years of age. But most children don’t like to have their temperature taken this way. Although taking a temperature under the armpit isn’t as precise, it will let you know whether your child has a fever. If so, you can then take a rectal temperature for the exact reading.
The following chart will help you decide which method to use.
| Age | Recommended technique |
|---|---|
| Birth to 2 years | First choice: Rectum (for an exact reading) |
| Second choice: Armpit (to check for fever) | |
| Between 2 and 5 years | First choice: Rectum |
| Second choice: Ear | |
| Third choice: Armpit | |
| Older than 5 years | First choice: Mouth |
| Second choice: Ear | |
| Third choice: Armpit |
TEMPERATURE TAKING TIPS
To get an accurate reading of your child’s temperature, you’ll need to make sure it’s done right. Here are some tips to help you.
Rectum
If you are using a glass thermometer, be sure that it is a rectal thermometer (the bulb is fatter than on an oral thermometer).
Clean the thermometer with cool, soapy water and rinse.
Shake it so that the mercury inside goes below 36°C (96.8°F).
Cover the silver tip with petroleum jelly (such as Vaseline).
Place your baby on his back with his knees bent.
Gently insert the thermometer in the rectum, about 2.5 cm (1 inch), while holding it with your fingers.
After at least 2 minutes, remove the thermometer and read the temperature.
Clean the thermometer.
Mouth
Because a glass thermometer can break if a child bites down on it, this method is not recommended for children younger than 5 years old.
Clean the thermometer with cool, soapy water and rinse.
Shake the thermometer so that the mercury inside goes below 36°C (96.8°F).
Carefully place the tip of the thermometer under your child’s tongue.
With your child’s mouth closed, leave the thermometer in place for 3 to 4 minutes.
Remove the thermometer and read the temperature.
Clean the thermometer.
Armpit
This method is usually used to check for fever in newborns and young children. If your child is under 2 years of age, and you find a fever, confirm it by taking a rectal temperature.
Use a rectal or oral thermometer.
Clean the thermometer with cool, soapy water and rinse.
Shake the thermometer so that the mercury inside goes below 36°C (96.8°F).
Place the tip of the thermometer in the centre of the armpit.
Make sure your child’s arm is tucked snugly against her body.
Leave the thermometer in place for at least 4 minutes.
Remove the thermometer and read the temperature.
Clean the thermometer.
Ear
Use a clean probe tip each time, and follow the manufacturer’s instructions carefully.
Gently tug on the ear, pulling it up and back. This will help straighten the ear canal, and make a clear path inside the ear to the ear drum.
Gently insert the thermometer until the ear canal is fully sealed off.
Squeeze and hold down the button for one second.
Remove the thermometer and read the temperature.
WHAT IS A NORMAL TEMPERATURE?
Now that you’ve taken the temperature, check the following chart to see whether your child has a fever. The normal temperature range varies, depending on what method you used.
| Measurement method | Normal temperature range |
|---|---|
| Rectum | 36.6°C to 38°C (97.9°F to 100.4°F) |
| Mouth | 35.5°C to 37.5°C (95.9°F to 99.5°F) |
| Armpit | 34.7°C to 37.3°C (94.5°F to 99.1°F) |
| Ear | 35.8°C to 38°C (96.4°F to 100.4°F) |
Footnotes
This information should not be used as a substitute for the medical care and advice of your physician. There may be variations in treatment that your physician may recommend based on individual facts and circ*mstances.
This information may be reproduced without permission and shared with patients and their families. Also available on the Internet at www.cps.ca
Canadian Paediatric Society, 2204 Walkley Road, Suite 100, Ottawa, Ontario K1G 4G8 telephone 613-526-9397, fax 613-526-3332
Articles from Paediatrics & Child Health are provided here courtesy of Oxford University Press
