Discharge Instructions: Taking a Rectal Temperature (Pediatric)

Discharge Instructions: Taking a Rectal Temperature (Pediatric)

You take a rectal temperature by placing a thermometer in your baby’s bottom. This method provides the most accurate reading. But do this only when instructed by your baby’s doctor. Use the steps on this sheet as a guide.

Rectal thermometer showing rectal safety stop to prevent over-insertionn.

Rectal thermometer showing a digital display.

  Caretaker hold up babies legs and inserting rectal thermometer.

Get the Thermometer Ready

  • Be sure to use a thermometer that is specifically designed for rectal use.

  • Remove the cover from the thermometer.

  • Wash the thermometer with warm soapy water; then rinse with clear water.

  • Wipe the thermometer dry or let it air dry.

  • Smear a bit of petroleum jelly or water-based lubricant on the tip.

Find a Comfortable Position for Holding Your Baby

  • Put your baby on his or her back on a firm surface.

  • Hold the baby’s ankles and lift both legs, as if changing a diaper.


  • Place your baby face down across your lap.

  • Use one hand to part the baby’s buttocks.

Take the Temperature

  • Follow the specific directions for using your digital thermometer.

  • Gently slip the tip of the thermometer into the rectum (the opening where bowel movements leave baby’s body), no farther than ¼ to ½ inch. Never insert the tip more than ½ inch.

  • Hold the thermometer in place until it beeps.

  • Slide the thermometer out. Read the temperature on the digital display. Normal rectal temperature is about 97.6°F (36.4 °C) to 100.2°F (37.9°C).

  • Before putting the thermometer away, clean it with soap and warm water.


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

When to Call Your Doctor

Call your doctor right away if your child has any of the following:

  • Bleeding from the area where you took the temperature

  • Fever:

    • In an infant under 3 months old, a rectal temperature of 100.4°F (38.0°C) or higher

    • In a child 3 to 36 months, a rectal temperature of 102°F (39.0°C) or higher

    • In a child of any age who has a temperature of 103°F (39.4°C) or higher

    • A fever that lasts more than 24-hours in a child under 2 years old, or for 3 days in a child 2 years or older 

    • Your child has had a seizure caused by the fever

  • Shaking chills