How should I take my child's temperature?

If you think your child has a fever, take his temperature. You can do this by placing a thermometer under your child's tongue, under his arm in the armpit, in his ear, or in the rectum. Make sure you use the right thermometer for that area of the body. Do not use fever strips, because they are not accurate.

If you choose the rectal method, make sure the thermometer is for the rectum. Before you use a digital thermometer, carefully read and follow the instructions on the package insert. Never insert the thermometer tip more than 1/2 inch in the rectum (or as you were taught). The tip of this thermometer is more round than mouth or armpit thermometers. Also, a rectal temperature is usually one degree higher than a mouth or armpit temperature.
You can take a child's temperature in any of the following ways:
  • Orally: Place the thermometer under the child's tongue (with the mouth closed) for 3 minutes.
  • Axillary: Place the thermometer in the child's armpit for 5 minutes
  • Rectally: If your pediatrician recommends the use of a rectal thermometer, discuss the proper procedure with him or her. Have your pediatrician demonstrate the correct use and reading of the temperature.

The best way to take you child’s temperature depends on the child’s age, cognitive level and condition. In general a temperature can be measured orally (in the mouth), rectally (in the anus), axillary (in the arm-pit), tympanic (in the ear canal) or skin (on the forehead).

  • An oral temperature is a common way to measure temperature. Using a clean, digital thermometer, place the tip of the thermometer under the tongue. Have the child close their mouth. Hold the thermometer in place to prevent injury. An accurate oral temperature requires the cooperation of the child. Therefore the child needs to be able to follow directions.
  • A rectal temperature us the most accurate measure of the child’s core or body temperature. Using a clean, digital thermometer, coat the end with a small amount of water soluble lubricant. Place the child across your lap or on the bed with the legs in the air or in a side-lying position. Turn on the thermometer and slowly insert it into the rectum, no further than ½ inch. Hold the thermometer in place to prevent injury. When it beeps, remove it and note the temperature.
  • An axillary temperature is easier to take, but not as accurate as a rectal temperature. To take an axillary temperature remove the child’s shirt and make sure the underarm area is dry. Hold or position the child securely and place the tip of the thermometer into the pit of the axilla. Hold the child’s arm snuggly to the side of the body to stabilize the thermometer. When the thermometer beeps, remove it and note the temperature.

When taking an oral, rectal or axillary temperature always use a digital thermometer. Glass thermometers can break and cause injury to the child.

  • A tympanic thermometer can be use to measure body temperature via the ear canal. Hold the child so their head will not move. Gentle pull the ear back and insert the probe into the ear canal hold the button until the temperature is displayed.
  • A temporal artery thermometer is simply moved over the child’s forehead to detect the skin temperature. They are quick and can be used even while the child is sleeping. However data on the validity of temporal artery thermometers is very limited.
  • A rectal temperature gives the most reliable reading for children younger than 5 years.
  • For children age 5 and older, an oral temperature (in the mouth) is the recommended method.
  • *You also may take an oral temperature for children age 3 and older.
  • A child’s or an infant’s temperature also can be taken in the ear (known as the tympanic method) or under the arm (known as the axillary method).

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.