Taking a Temperature (Child) 

If your child shows signs of illness and feels hot, use a thermometer to check his or her temperature. Always use a digital thermometer to check your child's temperature. Never use a mercury thermometer. 

A temperature taken in the bottom (rectally) provides the most accurate reading. For infants and toddlers, be sure to use a rectal thermometer correctly. A rectal thermometer may accidentally poke a hole in (perforate) the rectum. It may also pass on germs from the stool. Always follow the product maker’s directions for correct use. If you don’t feel comfortable taking a rectal temperature, use another method. When you talk with your child’s healthcare provider, tell him or her which method you used to take your child’s temperature. New research shows that a forehead (temporal artery) temperature may be reliable in infants younger than 3 months. 

Taking the temperature by mouth (oral) is also very accurate in children age 4 years and older. Ear (tympanic) and armpit (axillary) temperature readings are less accurate than oral or rectal readings. But they can be done on very young children, including infants. Ear temperatures aren’t accurate before age 6 months. Other methods, such as plastic strips and pacifier thermometers are not recommended. If you do not know how to use a thermometer, ask your nurse or pharmacist for instructions.

Use the following methods to take a child’s temperature, depending on age:

  • Younger than 3 months. Start with an armpit temperature. If that measures above 99.0ºF (37.2ºC), take a rectal or forehead temperature. You can use a digital multiuse thermometer for rectal or armpit temperatures. A special temporal artery thermometer is used for the forehead.

  • 3 months to 4 years. Take a rectal, armpit or forehead temperature. You can use a digital multiuse thermometer for rectal or armpit temperatures. You can use a digital ear thermometer for ear temperatures. A special temporal artery thermometer is used for the forehead.

  • 6 months and older. You can start using an ear (tympanic) thermometer. You can use a digital ear thermometer for ear temperatures.

  • Older than 4 years. Take an oral, armpit, forehead, or ear temperature. You can use a digital multiuse thermometer for rectal or armpit temperatures. You can use a digital ear thermometer for ear temperatures. A special temporal artery thermometer is used for the forehead.

Oral method

Range of normal: 98.6ºF (37.0ºC), up to 100.0ºF (37.8ºC).

Recommended age: Use this method for children older than age 4 or 5 years, only if they are cooperative.

  1. Take an oral temperature at least 30 minutes after your child has had anything hot or cold to eat or drink.

  2. Place the tip of the thermometer under your child's tongue. Make sure your child does not bite down on the thermometer.

  3. Have your child close his or her lips gently, without biting on the thermometer.

  4. Have your child keep the thermometer under the tongue until it beeps.

  5. Remove the thermometer and read the temperature on the display.

  6. Clean the thermometer with alcohol or soap and water after each use.

Armpit method

Range of normal: 97.6ºF (36.4ºC), up to 99.0ºF (37.2ºC)

Recommended age: Use this method for children younger than age 4 years or any uncooperative child.

  1. Make sure armpit is dry and your child does not have clothing between the arm and chest.

  2. Place the tip of the thermometer high up in the armpit.

  3. Hold your child's arm snug against his or her body with the thermometer in place until it beeps.

  4. Remove the thermometer and read the temperature on the display.

  5. Clean the thermometer with alcohol or soap and water after each use.

Rectal method

Range of normal: 99.6ºF (37.6ºC), up to 100.4ºF (38.0ºC).

Recommended age: Use this method for children younger than age 4 years

  1. Lubricate the tip of a rectal thermometer with petroleum jelly or a water-soluble lubricant.

  2. Lay your child face down across your lap, or on his or her side with knees bent toward the chest. Spread buttocks so that the anus can be easily seen.

  3. Hold the thermometer between your thumb and index finger with your hand resting on the buttocks. Slowly and gently insert the thermometer into the anus about 1 inch. The tip should slide in easily. Don't force it. This may cause injury.

  4. Don't let go of the thermometer! Hold it carefully in place until it beeps.

  5. Remove the thermometer and read the temperature on the display.

  6. Clean the thermometer with alcohol or soap and water after each use.

Ear method

Range of normal: 99.6ºF (37.6ºC), up to 100.4ºF (38.0ºC).

Recommended age: Any child older than 6 months

  1. If your child has been outside playing, take the temperature after he or she has been indoors for at least 15 minutes.

  2. Place a disposable cover on the probe. This is the part that will be inserted in the ear.

  3. Pull the earlobe back slightly, and insert the probe in the ear canal.

  4. Press the On button.

  5. Remove the thermometer after it beeps or otherwise shows it has finished taking the temperature.

  6. Read the temperature on the display.

Temporal artery method

Range of normal: Up to 100.4°F (38.0°C)

Recommended age: Any child older than 3 months. (New research shows that this method may be reliable in infants younger than 3 months.)

  1. Place the thermometer's sensor on your child's forehead, about halfway between the eyebrow and the hairline.

  2. Push the scan button. Keep it pressed down while you slowly slide the thermometer across the forehead toward the top of the ear. Be sure to keep the thermometer touching the skin.

  3. Stop moving the thermometer when you reach the hairline. Let go of the scan button.

  4. Lift the thermometer from your child's forehead and read the temperature on the display.

When to seek medical advice

Call your healthcare provider right away if any of these occur.

Infant under 3 months old:

  • Ask your child’s healthcare provider how you should take the temperature.

  • Rectal or forehead (temporal artery) temperature of 100.4°F (38°C) or higher, or as directed by the provider

  • Armpit temperature of 99°F (37.2°C) or higher, or as directed by the provider

Child age 3 to 36 months:

  • Rectal, forehead (temporal artery), or ear temperature of 102°F (38.9°C) or higher, or as directed by the provider

  • Armpit temperature of 101°F (38.3°C) or higher, or as directed by the provider

Child of any age:

  • Repeated temperature of 104°F (40°C) or higher, or as directed by the provider

  • Fever that lasts more than 24 hours in a child under 2 years old. Or a fever that lasts for 3 days in a child 2 years or older.

© 2000-2021 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.
Powered by Krames Patient Education - A Product of StayWell