Newborn care: how to take your newborn’s temperature

Reviewed by Sara Connolly, MD, FAAP, Board Certified Pediatrician

Keeping your baby happy and healthy is every parent’s job. If you think your baby may have a fever, your healthcare provider may ask you to take your baby’s temperature. Knowing how to get an accurate temperature reading is important to ensure the health of your baby.

In the first weeks and months of your baby’s life, only take her temperature in the rectum or under the armpit. These methods give you the most accurate readings possible. Ask your healthcare provider which method they recommend.

If a rectal temperature is suggested, clean the tip of the thermometer with rubbing alcohol or soap and water, then lubricate the tip of the thermometer with a water-soluble lubricant.

Hold your baby face down on your lap, or on a hard flat surface like a changing table. Or, lift your baby’s legs to his chest. Insert the thermometer about ¼ to ½ inch into the rectum. Stop if you feel any resistance. On most thermometers a beep will tell you that the temperature is complete.

If your baby’s temperature is 100.4 degrees Fahrenheit or higher when taking the temperature rectally, she may have a fever. Call your healthcare provider right away.

If your healthcare provider recommends taking your baby’s temperature under the armpit, hold your baby on your lap or on a changing table. Insert the tip of the thermometer in either armpit, making sure the bulb of the thermometer is touching the baby’s skin and wait for the beep. If the armpit temperature reading is 99 degrees Fahrenheit or higher, you may want to take a rectal temperature for a more accurate result.

Do not take your baby’s temperature if she has just had a bath. Wait at least 20 minutes after the bath to ensure an accurate result.

Never use a glass thermometer when taking your baby’s temperature. It can break and harm your baby. And taking your baby’s temperature orally is not safe.

No matter what type of thermometer you choose, follow the instructions carefully to make sure you get an accurate result. And be sure to call your healthcare provider whenever you suspect your newborn may be feeling ill.

Your baby’s healthcare provider can help make sure your baby gets the care he may need.