How to Take an Axillary Temperature

Medically reviewed by Drugs.com. Last updated on Feb 21, 2024.

What is it?

An axillary (AK-sih-lar-e) temperature (TEM-per-ah-chur) is when your armpit (axilla) is used to check your temperature. A temperature measures body heat. A thermometer (ther-MOM-uh-ter) is used to take the temperature in your armpit. An axillary temperature is lower than one taken in your mouth, rectum, or your ear. This is because the thermometer is not inside your body such as under your tongue.

Why do I need to check an axillary temperature?

An axillary temperature may be done to check for a fever. "Fever" is a word used for a temperature that is higher than normal for the body. A fever may be a sign of illness, infection or other conditions. A normal axillary temperature is between 96.6° (35.9° C) and 98° F (36.7° C). The normal axillary temperature is usually a degree lower than the oral (by mouth) temperature. The axillary temperature may be as much as two degrees lower than the rectal temperature. Body temperature changes slightly through the day and night, and may change based on your activity.

What kind of thermometer is used to take an axillary temperature?

A digital thermometer may be used to take an axillary temperature. It is a small hand-held device with a "window" showing your temperature in numbers. There are many kinds of digital thermometers. Most digital thermometers are easy to use and measure body temperature in less than a minute. Carefully read the instructions before using your digital thermometer. Digital thermometers can be bought at grocery, drug, or medical supply stores.
Glass thermometers with red or blue alcohol inside may also be used for axillary temperatures. Glass thermometers with galinstan (GAL-in-stan) may also be used to check an axillary temperature. Galinstan thermometers have a silver colored line, but will be marked "mercury-free" when you buy one. Be very careful using a glass thermometer to check an axillary temperature on infants and children. Infants and children may move suddenly and break the glass thermometer next to their skin. You may need to hold a glass thermometer in place for up to ten minutes in order to get a correct axillary temperature reading. Alcohol-filled and galinstan glass thermometers are harder than digital thermometers to find in regular grocery stores.
In the past, mercury (MER-kure-e) thermometers were used. This thermometer is a thin glass tube with a silver line inside. Mercury is inside the silver tip and line. Mercury is a toxic and hazardous chemical. The Environmental Protection Agency (EPA), the American Academy of Pediatrics (AAP), and other organizations warn against using mercury thermometers. If the thermometer breaks, the mercury may be breathed in or absorbed (soaked) into your skin. Mercury is bad for your health, as well as for the water, wildlife, and waste systems on earth.
If you have a mercury thermometer, replace it with a digital thermometer. You may also replace it with a glass thermometer having alcohol or galinstan instead of mercury in it. If your mercury thermometer breaks, do not touch the thermometer or the mercury. Do not try to clean up the spill. Open your windows to air out the area. Take children and pets out of the area right away. Contact the following:

24-Hour Nationwide Poison Control Hotline
National Capital Poison Center
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Phone: 1- 800 - 222-1222
Web Address: http://www.poison.org

How do I use a digital thermometer?

Wait at least 15 minutes after bathing or exercising before taking your axillary temperature.

Take the thermometer out of its holder.
Put the tip into a new throw-away plastic cover. If you do not have a cover, clean the pointed end (probe) with soap and warm water or rubbing alcohol. Rinse it with cool water.
Put the end with the covered tip securely in your armpit. Hold your arm down tightly at your side.
Keep the thermometer in your armpit until the digital thermometer beeps.
Remove the thermometer when numbers show up in the "window".
Read the numbers in the window. These numbers are your temperature. Add at least 1 degree to the temperature showing in the window.
Your caregiver may want you to keep a temperature record. Write down the time and your axillary temperature each time you take it.
Remove or eject the throw-away cover if you used one.
Place the thermometer back in its holder.

How do I use a glass thermometer?

Wait at least 15 minutes after bathing or exercising before taking your axillary temperature.

Take the thermometer out of its holder.
Hold the thermometer by the end opposite the colored or silver tip.
Clean the thermometer with soap and warm water or rubbing alcohol. Rinse with cool water.
Turn the thermometer in your hand until you see the line. The line should read less than 96° F (35.6° C). If the line reads more than 96° F (35.6° C), firmly shake the thermometer downward several times. Shake the thermometer over a couch or bed. This will keep it from breaking if it slips out of your hand.
Check the thermometer to make sure it reads 96° F (35.6° C) or less.
Gently pat your armpit with a tissue. Do not rub when drying your armpit because rubbing warms the skin.
Put the end with the colored or silver tip under your arm. Hold your arm down tightly at your side.
Keep the thermometer under your arm for 5 minutes or longer.
Remove the thermometer without touching the tip.
Gently wipe the thermometer with a tissue.
Hold the thermometer at eye level.
Slowly turn the thermometer until you see the line. Each long mark is the same as 1 degree. Short marks are the same as 0.2 degree.
Your caregiver may want you to keep a temperature record. Write down the time and your temperature each time you take it.

Care Agreement

You have the right to help plan your care. To help with this plan, you must learn how to take an axillary temperature. You can then discuss your treatment options with your caregiver. You can work with your caregiver to decide what care will be used to treat you. 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.

Further information

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

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