Assessment Library

How to Take an Underarm Temperature on a Child

Get clear, parent-friendly guidance on how to use a thermometer under the arm, what an underarm temperature reading may mean for fever, and when this method is most useful for babies, infants, and children.

Answer a few questions to get personalized guidance on the underarm temperature method

Whether you’re trying to take a child’s temperature under the arm, wondering how accurate underarm temperature is, or unsure if the reading suggests fever, this quick assessment can help you feel more confident about your next step.

What is your biggest concern about using the underarm temperature method right now?
Takes about 2 minutes Personalized summary Private

When parents use the underarm temperature method

The underarm temperature method, also called an axillary temperature for children, is often used when parents want a simple, noninvasive way to check for fever. It can be especially helpful if a baby or child is sleeping, uncomfortable, or resistant to other thermometer methods. Because underarm readings can run a little lower than internal body temperature, technique matters. A careful reading can give useful information, but it’s important to know how to place the thermometer correctly and how to interpret the number you see.

How to use a thermometer under the arm correctly

Place the tip in dry skin

Put the thermometer high in the center of the armpit so the tip touches skin, not clothing. If the underarm is damp, gently dry it first for a more reliable reading.

Hold the arm snugly against the body

Keep your child’s arm pressed firmly against their side the entire time. This helps trap heat around the thermometer and improves the accuracy of the underarm temperature reading.

Wait until the thermometer finishes

Leave the thermometer in place until it signals that the reading is complete. Removing it too early is a common reason underarm readings seem inconsistent.

Why underarm readings may seem confusing

Underarm temperatures can read lower

An armpit temperature for infant or child may be lower than a rectal, oral, or ear reading. That does not always mean the child does not have a fever, but it does mean interpretation should be cautious.

Movement affects the result

If your child wiggles, lifts their arm, or the thermometer shifts position, the reading may not reflect their true temperature. This is one reason parents ask how accurate is underarm temperature.

Technique changes the number

Small differences in placement, timing, or whether the underarm is fully closed can change the result. If you are checking fever with an underarm thermometer, consistency in technique is important.

Understanding an underarm temperature reading for fever

If you are trying to decide whether an underarm temperature reading means fever, remember that the number should be considered along with your child’s age, symptoms, and how they are acting overall. Underarm readings are often used as a screening method rather than the most precise option. If the reading seems borderline, unexpectedly low, or does not match how sick your child appears, many parents choose to repeat the temperature using the same method carefully or ask a healthcare professional which method is best for their child’s age.

Tips for babies, infants, and older children

For babies

When learning how to take armpit temperature baby, try checking when your baby is calm or resting. Gentle positioning and a dry underarm can make the process easier.

For infants

With an armpit temperature for infant, keep the thermometer steady and the arm tucked in securely. If your infant is fussy, swaddling the opposite arm may help reduce movement.

For older children

If you need to take child temperature under the arm, explain that they need to keep their arm down like a statue until the thermometer beeps. A simple distraction can help them stay still.

Frequently Asked Questions

How do I take an underarm temperature on a child the right way?

Place the thermometer tip high in the center of a dry armpit, then hold your child’s arm firmly against their body until the thermometer signals that it is done. Good skin contact and keeping the arm closed are key parts of the underarm temperature method for kids.

How accurate is underarm temperature for children?

Axillary temperature for children can be useful, but it is generally considered less precise than some other methods. It works best when done carefully and consistently. If the reading does not match how your child looks or feels, you may need to repeat it or ask a healthcare professional about the best method for your child’s age.

What does an underarm temperature reading mean for fever?

An underarm temperature reading for fever can help screen for a possible fever, but underarm readings may run lower than core body temperature. If the number seems close to a fever range or your child seems unwell despite a lower reading, use caution and consider getting additional guidance.

Can I use the underarm method for a baby or infant?

Yes, many parents use an armpit temperature for infant or baby because it is simple and noninvasive. Proper placement, a dry underarm, and keeping the arm snug against the body are especially important in younger children.

Why are my underarm thermometer readings inconsistent?

Inconsistent readings often happen when the thermometer shifts, the underarm is damp, the arm is not held tightly enough, or the thermometer is removed too soon. If you are trying to check fever with an underarm thermometer, repeating the reading with careful technique may help.

Still unsure about the underarm temperature method?

Answer a few questions for personalized guidance on how to check fever underarm thermometer readings, improve your technique, and understand when an underarm reading may need closer follow-up.

Answer a Few Questions

Browse More

More in How To Take Temperature

Explore more assessments in this topic group.

More in Fever, Colds & Common Illnesses

See related assessments across this category.

Browse the full library

Find more parenting assessments by category and topic.

Related Assessments

Best Thermometer By Age

How To Take Temperature

Cleaning A Thermometer

How To Take Temperature

Digital Thermometer Instructions

How To Take Temperature

Ear Thermometer Use

How To Take Temperature