Discharge Instructions: Taking an Axillary Temperature (Pediatric)

You take an axillary (armpit) temperature by holding the thermometer under your baby’s arm for 4 to 5 minutes. Do this with care to get a correct reading. Note that taking a child’s temperature under the arm is less accurate than taking the temperature in the rectum. That's especially the case for babies younger than 3 months old.

Closeup of adult raising baby's arm to place digital thermometer in armpit.

Woman holding digital thermometer in baby's armpit.

Digital thermometer.

Get the thermometer ready

  • Use a thermometer that is made only for underarm use.

  • Take the cover off.

  • Clean the thermometer before each use.

  • Be sure the thermometer is at room temperature when you use it.

Position your baby

  • Hold your baby on your lap. Or lay the baby on his or her back on a firm surface.

  • Gently lift your baby’s arm.

  • Place the tip of the thermometer in the fold of the baby’s armpit. To get a true reading, the thermometer must rest directly against baby’s skin on all sides.

  • Lower the arm back down to your baby’s side.

Take the temperature

  • Follow the instructions for using your thermometer.

  • Keep your baby’s arm against his or her side for 4 to 5 minutes. This keeps the thermometer in place and gives an accurate reading.

  • When the thermometer beeps, remove it and read the temperature on the display.

  • Normal axillary temperature is about 97.6°F (36.4°C) to 99.4°F (37.4°C). An axillary temperature is often 1 degree lower than oral or rectal temperatures. So it can help you gauge whether your child may have a fever. But it's not the most reliable at any age.

  • Before putting the thermometer away, clean it with soap and warm water. And put the cover back on.

Follow-up

Make a follow-up appointment as directed by our staff.

When to call your child's healthcare provider

Call your baby's healthcare provider right away if your baby has any of these:

  • Bleeding from where you took the temperature

  • Fever of 99°F (37.2°C) or higher for a temperature taken under the arm in a baby younger than 3 months

  • Fever of 101°F (38.3°C) or higher for an armpit temperature in a child age 3 months to 36 months (3 years)

  • Fever that rises to 104°F (40°C) in a child of any age 

Online Medical Reviewer: Donna Freeborn PhD CNM FNP
Online Medical Reviewer: Heather Trevino
Online Medical Reviewer: Liora C Adler MD
Date Last Reviewed: 4/1/2020
© 2000-2020 The StayWell Company, LLC. 800 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.