Taking Your Baby's Temperature

Author: Karen McCumiskey, MS, RNC, Perinatal Education Coordinator, Good Samaritan University Hospital

You often can tell if your baby is warmer than usual by feeling their forehead but only a thermometer can tell how high the temperature. Always use a digital thermometer to check your baby’s temperature. Your baby’s temperature and other signs of illness will help your doctor recommend treatment that is best for them. Mercury thermometers should not be used. The American Academy of Pediatrics (AAP) encourages parents to remove mercury thermometers from their homes to prevent accidental exposure and poisoning. Digital pacifier thermometers and fever strips are not recommended.

How to use a digital multi-use thermometer

Rectal temperature

• If your child is younger than three years, taking a rectal temperature gives the best reading—especially for babies younger than thee months. The following is how to take a rectal temperature:
• Clean the end of the thermometer with rubbing alcohol or soap and water. Rinse it with cool water. Do not rinse it with hot water.
• Put a small amount of lubricant, such as petroleum jelly, on the end.
• Place your child belly down across your lap or on a firm surface. Hold them by placing your palm against their lower back, just above their bottom. Or place your child face up and bend their legs to their chest. Rest your free hand against the back of the thighs.
• With the other hand, turn the thermometer on and insert it 1/2 inch to 1 inch into the anal opening. Do not insert it too far. Hold the thermometer in place loosely with two fingers, keeping your hand cupped around your child’s bottom. Keep it there for about one minute, until you hear the “beep.” Then remove and check the digital reading.      

Be sure to label the rectal thermometer so it's not accidentally used in the mouth.

Call your doctor immediately if your child:

• Has a rectal, ear or temporal artery temperature of 100.4 F (38 C) or higher
• Is unusually drowsy, fussy or looks sick
• Has been in a very hot p[lace such as an overheated car
• Has other symptoms, such as a stiff neck, severe headache, severe sore throat​, ​severe ear pain, an unexplained rash, or repeated vomiting or diarrhea
• Has had a seizure

Types of Digital Thermometers

The following are three types of digital thermometers. While other methods for taking your child’s temperature are available, such as pacifier thermometers or fever strips, they are not recommended at this time. Ask your baby’s doctor for advice.

From the American Academy of Pediatrics:

• Fever and Your Baby
• Fever without Fear: Information for Parents

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