Always use a digital thermometer to check your temperature. Because of the potential for mercury exposure or ingestion, glass mercury thermometers have been phased out and are no longer recommended.

No matter which type of thermometer you use, take these precautions:

• Read the instructions that came with the thermometer.
• Wash your hands with soap and warm water before using the thermometer.
• Clean the thermometer before and after each use with rubbing alcohol or soap and lukewarm water.
• Don't use the same thermometer for both oral and rectal temperatures. Get two and label which is used where.
• Wait at least 6 hours after taking medications that can lower your temperature, like acetaminophen (Tylenol, others), ibuprofen (Advil, Motrin IB, others) or aspirin.

Oral temperature

You'll need an oral thermometer, used in the mouth.

1. If you've been eating or drinking, wait 30 minutes before you take a temperature by mouth.
2. Turn on the digital thermometer. Place the thermometer tip under your tongue.
3. Close your mouth around the thermometer for the recommended amount of time or until the thermometer beep indicates it's done.
4. Remove the thermometer and read the number.

Ear temperature

A digital ear thermometer uses an infrared ray to measure the temperature inside the ear canal.

1. Turn on the digital thermometer. Gently place it in your ear canal no further than indicated by the instructions that came with the device.
2. Hold the thermometer tightly in place until you hear the thermometer beep indicating it's done.
3. Remove the thermometer and read the number.

Temporal artery temperature

Temporal artery thermometers use an infrared scanner to measure the temperature of the temporal artery in your forehead.

1. Turn on the digital thermometer.
2. Gently sweep it across your forehead and read the number.

Armpit temperature

A digital thermometer can be used in your armpit, if necessary. But armpit temperatures are typically less accurate than oral temperatures.

1. Turn on the digital thermometer. Place the thermometer under your armpit, making sure it touches skin, not clothing.
2. Hold the thermometer tightly in place until you hear the thermometer beep indicating it's done.
3. Remove the thermometer and read the number.

This article is written by Mayo Clinic Staff.

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Information in this post was accurate at the time of its posting. Due to the fluid nature of the COVID-19 pandemic, scientific understanding along with guidelines and recommendations may have changed since the original publication date. 

Check the Centers for Disease Control and Prevention website for additional updates on COVID-19. For more information and all your COVID-19 coverage, go to the Mayo Clinic News Network and mayoclinic.org.

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