When using an electronic thermometer when do you measure oral temperature?

For advice about taking a temperature in a child under 5, see how to take a baby's or young child's temperature.

Using a digital thermometer

One way to check your temperature is to use a digital thermometer. You can buy these from supermarkets and pharmacies.

To use a digital thermometer:

1. Clean the tip with cold water and soap, then rinse it.
2. Turn the thermometer on.
3. Put the tip under your tongue, towards the back of your mouth.
4. Close your lips around the thermometer.
5. Wait until it beeps or flashes.
6. Check the temperature on the display.

Information:

You can also use a digital thermometer in your armpit. Make sure you keep your arm tight against your body until the thermometer beeps or flashes.

Digital ear thermometers

If you use a digital ear thermometer, follow the instructions that come with it.

You usually need to gently pull your ear up and back before putting the thermometer in your ear. This helps you get a more accurate temperature.

Important: Other thermometers

Do not use a glass thermometer or a forehead strip.

Glass thermometers can be dangerous and forehead strips are not accurate.

If you do not have a thermometer

You can often still tell if you have a high temperature even if you do not have a thermometer.

Touch your chest and back. If they feel hotter than usual, you may have a high temperature. You may also have other symptoms such as feeling shivery (chills).

Touching your forehead is not a very accurate way of checking your temperature.

What is a high temperature?

Normal body temperature is different for everyone and changes during the day.

A temperature of 38C or more is usually considered a high temperature (fever).

Important

It's not always easy to take a temperature accurately.

If you feel hot or shivery, you may have a high temperature even if a thermometer says your temperature is below 38C.

What should I do if I have a high temperature?

Try to stay at home and avoid contact with other people if you have a high temperature or do not feel well enough to do your normal activities.

Clean the thermometer with soap and warm water or rubbing alcohol before and after you use it. Do not submerge it in water.

• To take an oral temperature , put the tip under your tongue as far as it can go. Close your lips gently around the thermometer. Do not bite the thermometer. Relax and breathe through your nose. Keep the thermometer under your tongue until it beeps. You can take your child's temperature in his or her mouth at 4 or 5 years old. Wait 20 to 30 minutes after you or your child finish eating or drinking to take an oral temperature.
• To take an underarm temperature , put the tip in your or your child's armpit. Make sure the thermometer is touching skin and not clothes. Squeeze your arm against your body to hold the thermometer in place. Keep the thermometer in your armpit until it beeps.
• To take a temporal temperature , push down on the button to turn it on. Swipe the thermometer from one temple to the other and behind the ear until it beeps.
• To take an ear temperature , gently pull the adult ear up and back. When you take your child's temperature, pull the ear down and back. Put the thermometer tip into your ear. Do not use force or push hard. The thermometer tip should not touch the ear drum. Hold it until it beeps.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

© Copyright Merative 2022 Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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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