Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

First Aid & Emergencies

Font Size

Body Temperature

Why It Is Done

Body temperature is checked to:

  • Detect fever.
  • Detect abnormally low body temperature (hypothermia) in people who have been exposed to cold.
  • Detect abnormally high body temperature (hyperthermia) in people who have been exposed to heat.
  • Help monitor the effectiveness of a fever-reducing medicine.
  • Help plan for pregnancy by determining if a woman is ovulating.

How To Prepare

Take your temperature several times when you are feeling well to find out what is normal for you. Check your temperature in both the morning and evening, since body temperature can vary by as much as 1°F (0.6°C) throughout the day.

Wait at least 20 to 30 minutes after smoking, eating, or drinking a hot or cold liquid before taking your temperature. Also, wait at least an hour after vigorous exercise or a hot bath.

Several different types of thermometers are available:

  • Electronic thermometers camera.gif are plastic and shaped like a pencil, with a display window at one end and the temperature probe at the other end. They work by measuring how well electricity travels through a wire. Electronic thermometers are used in the mouth, rectum, or armpit. They are easy to use and easy to read. If you buy an electronic thermometer, check the package for information about its accuracy.
  • Ear thermometers camera.gif are plastic and come in different shapes. They use infrared energy to measure body temperature. The small cone-shaped end of the thermometer is placed in the ear, and body temperature is shown on a digital display. The results appear within seconds. Some models also show the corresponding oral and rectal readings.
  • Temporal artery thermometers are electronic devices that measure body temperature on the skin over an artery in the forehead (superficial temporal artery). The device has a small "cup" that is moved across the skin over the artery. Infrared energy is used to determine the temperature. When used correctly, temporal artery thermometers are accurate for measuring body temperature.1, 2
  • Disposable thermometers are thin flat pieces of plastic with colored dots and temperature markings on one end. The color of the dots shows the temperature. Disposable thermometers can be used in the mouth or rectum. A patch form can be used on a baby's skin to measure temperature continuously for 48 hours. These thermometers are safe, but they are not as accurate as electronic or ear thermometers. They do not contain glass, latex, or mercury. You can reuse the thermometer during an illness and then throw it away.
  • Forehead thermometers use skin temperature to determine body temperature. They are thin pieces of plastic with numbers on them. You press the strip against a person's forehead, and the temperature makes some numbers change colors or light up. These thermometers are not very accurate.
  • Pacifier thermometers are shaped like a baby's pacifier but have a display that shows the temperature. You place the pacifier in your child's mouth to measure temperature. These thermometers may take longer to get a reading and are not as accurate as other types.

Glass thermometers containing mercury are no longer recommended. If you have a glass thermometer, contact your local health department for instructions on how to dispose of it safely. If you break a glass thermometer, call your local poison control center immediately.

1 | 2 | 3 | 4 | 5 | 6 | 7 | 8

WebMD Medical Reference from Healthwise

Last Updated: November 14, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

First Aid A-Z

  • There are no topics that begin with 'O'
  • There are no topics that begin with 'Q'
  • There are no topics that begin with 'U'
  • There are no topics that begin with 'X'
  • There are no topics that begin with 'Y'
  • There are no topics that begin with 'Z'

Today on WebMD

Antibiotic on hand
3d scan of fractured skull
Father putting ointment on boy's face
Person taking food from oven
sniffling child
wound care true or false
caring for wounds
Harvest mite

Pollen counts, treatment tips, and more.

It's nothing to sneeze at.

Loading ...

Sending your email...

This feature is temporarily unavailable. Please try again later.


Now check your email account on your mobile phone to download your new app.

WebMD the app

Get first aid information. Whenever. Wherever... with your iPhone, iPad or Android.

Find Out More