How to Use a Baby Thermometer

There are two ways to take a baby's temperature: axillary, or under the arm, and rectal, or in the anus.

Instructions

Difficulty: Easy

Things You’ll Need:

• Digital Thermometers
• Thermometers

Axillary

1. Use either a rectal or oral thermometer to take an axillary temperature.
2. Shake down the thermometer until it reads below 95.9 degrees, if you're using the glass-mercury type, or turn on the thermometer, if you're using the digital type.
3. Insert the thermometer into the armpit and hold down the baby's arm so that the end of the thermometer is completely surrounded by skin.
4. Leave the thermometer in place for 2 to 3 minutes if using the glass-mercury type. For the digital type, wait until the thermometer signals that the process is complete.
5. Read the thermometer where the line of mercury ends or, if using a digital thermometer, read the display.

Rectal

6. Use a rectal thermometer. Never use an oral thermometer to take a rectal temperature.
7. Shake down the thermometer until it reads below 95.9 degrees, if you're using the glass-mercury type, or turn on the thermometer if you're using the digital type.
8. Coat the end of the thermometer with petroleum jelly or another lubricant.
9. Insert it about 1 inch into the anus, or until the probe is completely covered.
10. Hold for 2 to 3 minutes or, if using a digital thermometer, wait until it signals that it is done. Try to keep the baby still.
11. Read the thermometer where the line of mercury ends or, if using a digital thermometer, read the display.

Tips & Warnings

• Digital thermometers work faster, which may be helpful with a small baby. But glass-mercury thermometers are just as accurate and a lot less expensive.
• Clean a glass-mercury thermometer with soap and water, and sterilize it by soaking it in alcohol.
• Clean a digital thermometer by following the manufacturer's instructions.
• Clean a glass-mercury thermometer with soap and water, and sterilize it by soaking it in alcohol.
• Clean a digital thermometer by following the manufacturer's instructions.
• For babies 6 months and younger, use the axillary method unless the doctor instructs otherwise. Putting a thermometer in the rectum may cause injury.