Temperature Check

Christine Sweeney, LICSW Program Manager, Parent Connection, BIDMC

MARCH 03, 2016

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It’s a really good idea to know how to take your baby’s temperature before you think your baby might be sick. For one thing, just thinking your newborn might have a fever is stressful. You don’t need the added stress of then trying to find the thermometer at 2am and then figuring out how to take a rectal temperature for the first time.

When should I check my baby's temperature? 
Whenever you notice a change in baby's usual behavior: 

  • S/He is sleepier or less active, or than usual. 
  • More irritable or fussy than usual. 
  • Isn't hungry or eating as well as usual. 
  • Baby’s body feels warmer or cooler than usual. 
  • His/Her color is rosy or flushed, very pale or mottled (looks like marble.) 

What should I use to take my baby's temperature? 

  • Use a basic digital thermometer. Most can be used rectally, orally or under the arm and can be purchased for under $10.00 in any drug store. Glass or mercury thermometers should never be used and should be disposed of properly. 

 What method should I use to take my baby's temperature? 

  • From newborn up to 3 months, the American Academy of Pediatrics recommends taking rectal temperatures. 
  • For 3 months to 3 years it’s still fine to take the temperature may be taken rectally, axillary (under the arm) or in the ear (this requires a special thermometer.) 

How do I take my baby's temperature? 
Taking a rectal temperature: 

  • Clean the end of the thermometer with rubbing alcohol or soap and water: rinse in lukewarm water and dry. Apply a small amount of lubricant, such as petroleum jelly on the end. 
  • Place the baby tummy down across your lap. Hold the baby by placing your palm against his lower back. OR, place the child face up and bend his legs to the chest. Rest your free hand against the back of his thighs. 
  • With your other hand, turn the thermometer on, and insert it 1/2 to 1 inch into the anal opening (be sure not to insert it too far). Hold the thermometer in place loosely with 2 fingers, keeping your hand cupped around the baby's bottom. When you hear the thermometer beep, remove it and check the reading. 
  • Re-clean. Label the thermometer so it is not accidentally used in the mouth. 

Taking an axillary temperature: 

  • Turn on the thermometer and place the small end in the baby's armpit. Make sure it is touching only skin, not clothing.
  • Gently hold that baby's arm in place until the thermometer beeps. 


Notify your baby's care provider for a rectal temperature over 100, an axillary temperature over 99.6 or a low temperature below 97.

Above content provided by Beth Israel Deaconess Medical Center. For advice about your medical care, consult your doctor.
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