How to Read a Fever Thermometer

When you think that your child has a fever, use a fever thermometer to take her temperature. There are three main types of thermometers–digital, mercury and plastic strip. The plastic strip type can give you an idea of whether your child has a fever, but it is not good for getting an exact reading. Mercury thermometers used to be the standard, but there is some concern about poisoning, so the American Academy of Pediatrics no longer recommends them. Different digital thermometers allow you to take temperatures from different places–in the mouth, rectum, ear or armpit.

Digital Thermometer

Step 1

Turn the thermometer on. Often, it will briefly show the last temperature reading, then go into a neutral state, such as a series of dashes. You must wait until it’s in the neutral state to take a temperature.

Step 2

Place the thermometer correctly. If you have an ear thermometer, it must go in the ear. Other thermometers can go in the rectum, mouth or under the armpit. The rectal temperature will be the most accurate.

Step 3

Wait for the thermometer to beep. This can take anywhere from a few seconds to two minutes, depending on the thermometer you’ve purchased.

Step 4

Look at the reading screen. Once the thermometer beeps, it’s ready to read. The display screen will show your child’s temperature as a digital number.

Mercury Thermometer

Step 1

Shake the thermometer to move the mercury to the bottom.

Step 2

Position the thermometer to take the temperature. A mercury thermometer should go in the rectum, mouth or armpit.

Step 3

Wait two minutes.

Step 4

Rotate the thermometer until you can see the reading. You can only see the mercury reading from certain angles. Hold it horizontally in front of you. Rotate it until you can see a silver bar. The end of the bar will match up with a number reading. This is the child’s temperature.