Taking your baby's temperature

A normal temperature for your baby ranges from 97.6 F to 100.3 F. You only need to take your baby's temperature when you think she has a fever or is ill.

You can take your baby's temperature by placing a thermometer in your baby's armpit. This gives you the axillary temperature.

Your baby's health care provider may ask you to take a rectal temperature. If this is requested, please follow the instructions below on how to take a rectal temperature.

How to take an axillary temperature:

  • Sit with your baby on your lap.
  • Lift your baby's arm and place the smaller end of the thermometer well into the armpit.
  • Lower your baby's arm and hold it close to his body.
  • Press the start button.
  • Keep your baby's arm down and the thermometer in place until it beeps.
  • Remove the thermometer and read it.

How to take a rectal temperature:

  • Calm your baby.
  • Place a small amount of water-based lubricant (such as K-Y® Jelly) on the tip of the thermometer. (Some thermometers come with thin covers to use while taking a rectal temperature.)
    Avoid using petroleum jelly, like Vaseline®, because you may not get an accurate reading.
  • Lay your baby over your lap, lying him on his stomach. Support his head with your thigh. Or, place him in the position you would use to change his diaper and lift his legs.
  • Undo his diaper and leave it under him.
  • Spread his buttocks with one hand. With the other hand, insert the tip of the thermometer about one-quarter to one-half an inch into the rectum, just until you can no longer see the tip.
  • Hold the thermometer between your thumb and index finger.
  • Press the start button.
  • Wait until the thermometer beeps.
  • Remove the thermometer and read it.

Other ways of taking your baby's temperature are by:

  • forehead: This is a temporal artery thermometer. It takes your baby's temperature by scanning the temporal artery, which runs across the forehead down to the ear. This type of thermometer is found in most stores. Follow the package directions.
  • ear: This is a tympanic thermometer. It is not as reliable to use and needs practice to be used correctly. This type of thermometer is not recommended for newborns.

Source: Allina Health's Patient Education Department, Beginnings: Pregnancy, Birth and Beyond, seventh edition, ob-ah-90026
First Published: 10/04/2002
Last Reviewed: 12/02/2015


Do not use tape thermometers or pacifier thermometers. They are not accurate.

Mercury thermometers are no longer used because of health issues. If you have one and want to dispose of it, do not throw it in the garbage.

Take your mercury thermometer, and any other products that contain mercury, to a household hazardous waste collection facility.