Taking Your Child's Oral (By Mouth) Temperature

Taking your child's temperature can help you know if they have a fever. For most kids 4 years and older, you can take an oral (by mouth) temperature with a digital thermometer.

Take your child's temperature with a digital thermometer labeled for oral use. Follow the instructions that came with the thermometer. In general:

1. Clean the thermometer before use. You can wipe it with rubbing alcohol on a cotton pad or wash it with soap and water, then rinse with cool water.

2. Turn the thermometer on.

3. Place the tip of the thermometer under your child's tongue and ask your child to close their lips around it. Tell your child not to bite the thermometer or talk, and to breathe normally through the nose.

4. Wait with your child until the thermometer signals that the temperature is ready to view.

5. Remove the thermometer and write down the number on the thermometer screen and the time of day.

6. Turn the thermometer off.

7. Clean the thermometer with either rubbing alcohol or soap and water. 

Reminders:

• An oral temperature of 100°F (37.8°C) or greater is considered a fever. 

• Do not use an oral thermometer in kids:

  • Under 4 years old

  • 4 years and older if they have trouble following directions or can't hold a thermometer under their tongue

Take a rectal (in the bottom), temporal (forehead), ear, or axillary (armpit) temperature instead.

• Wait 20–30 minutes after your child has had anything to eat, drink, or has had a bath to take the temperature. Make sure there is no food or gum in your child's mouth. 

• Never use a glass/mercury thermometer. They can break and cut your child and expose them to mercury (a harmful chemical).

• You have questions about how to use the thermometer.

• Your child has a fever.