Sign In
Boston Public Health Commission Home

HOME > WHAT WE DO BY TOPIC > INFECTIOUS DISEASES > INFECTIOUS DISEASES A-Z > Fever in Children - Taking a Temperature

Fever in Children - Taking a Temperature

What are the different ways to take a child’s temperature?

Rectal (by the bottom), axillary (under the arm), oral (in the mouth) and tympanic (in the ear)

Which method should I use for taking my child’s temperature?

Be sure to read the package directions before using a thermometer and ask your health care provider or pharmacist if you have questions.  Never leave a child unattended when taking a temperature.  If you are unsure how to take a rectal temperature, be sure to talk your baby’s healthcare provider first.  If your child is under 3 months of age and has a rectal temperature above 100.3 ºF, be sure to call your baby’s healthcare provider right away. Never use a mercury thermometer.  If a mercury thermometer breaks this could release mercury which is a toxic substance.                                                 

AgeRecommended Technique
Newborn to 3 months​First choice: Rectum​
Three months to 5 years​

First choice: Rectum

Second choice: Ear

Third choice: Armpit​

Older than 5 years​

First choice: Mouth

Second choice Ear

Third choice: Armpit​

 
Rectal
Be sure to use a rectal thermometer which is specially designed for taking a temperature in the rectum.  It usually has a silver tip that is a little more rounded.
 
How to take a rectal temperature
  1. Clean the thermometer with cool, soapy water and rinse.
  2. Cover the silver tip with petroleum jelly (such as Vaseline®).
  3. Lay child belly down on a firm surface and keep your palm along his or her lower back just above the child’s bottom. 
  4. With the other hand, gently put the thermometer in the rectum (anal opening) about ½ to 1 inch (about the length of the silver tip).  Stop if you feel any resistance.  Do not put in any further.
  5. Hold the thermometer in place with your two fingers, keeping your hand cupped around the child’s bottom. 
  6. Hold the thermometer in place for the amount of time in the manufactures directions or until you hear a “beep.”  Remove the digital thermometer and read the temperature.  Normal temperature is 97.9ºF to 100.3ºF.
  7. Clean the thermometer.
Oral
Do not let the child drink hot or cold liquids for 15 minutes before taking the temperature (this will change his/her mouth temperature) and make sure there is no gum or candy in the child’s mouth.
 
How to take an oral temperature
  1. Clean the thermometer with cool, soapy water and rinse.
  2. Carefully place the tip of the thermometer under you child’s tongue towards the back of the mouth.
  3. Have the child close his or her mouth but do not bite down on the thermometer or talk.  Remind the child to relax and breathe normally through the nose. 
  4. Hold the thermometer in place for the amount of time written in the manufactures directions or until you hear a “beep.” 
  5. Remove the digital thermometer and read the temperature.  Normal temperature is 95.9ºF to 99.5ºF.
  6. Clean the thermometer.
Ear
Be sure to use a special ear thermometer.  Do not use it in the mouth, bottom or under the arm.  Follow the manufacture’s directions for use.
 
How to take an ear temperature
  1. Use a clean probe tip each time.
  2. Gently position the ear by pulling back and up on the top part of the ear.  This will help straighten the ear canal and make it easier to insert correctly.
  3. Gently insert the thermometer in the ear canal until it fits snugly. 
  4. Squeeze and hold down the button for the amount of time written in the manufactures directions.
  5. Remove the digital thermometer and read the temperature.  Normal temperature is 96.4ºF to 100.4ºF.
Axillary (under the arm)
This method is not as accurate as other methods.  You may need to use either a rectal or oral thermometer to get an accurate reading. 
 
How to take an axillary temperature
  1. Clean the thermometer with cool, soapy water and rinse.
  2. Place the tip of the thermometer in the center of the armpit.  The thermometer should be touching skin and not clothing. 
  3. Make sure you child’s arm is tucked snugly against the body.
  4. Leave the thermometer in place for about 1 minute, or until you hear the “beep.”
  5. Remove the digital thermometer and read the temperature.  Normal temperature is 94.5ºF to 99.1ºF.
  6. Clean the thermometer.
OnlineNewsRoomStyles
Boston Public Health Commission
1010 Massachusetts Ave, 6th Floor, Boston, MA 02118.
Phone:(617) 534-5395 Email: info@bphc.org