When Your Infant or Child Has a Fever

A normal temperature is about 98.6°F when taken orally (by mouth). Temperatures taken rectally (by rectum) usually run 1° higher than those taken orally. So a normal temperature is about 99.6°F when taken rectally. Many doctors define a fever as an oral temperature above 99.4°F or a rectal temperature above 100.4°F.

The most accurate way to take your child's temperature is orally or rectally with a digital thermometer. In a child younger than about 4 years, take the temperature rectally. In an older child, take it orally.

• Mercury thermometers should not be used. Mercury is an environmental toxin, and you don't want to risk exposing your family to it. If you have a mercury thermometer at home, you should remove it and use a digital thermometer.
• Don't bundle your baby or child up too tightly before taking his or her temperature.
• Never leave your child alone while taking his or her temperature.
• Be sure you use the right thermometer. Read the package instructions to see if you have an oral or rectal thermometer.
• If you're taking your child's temperature rectally, coat the tip of the thermometer with petroleum jelly (brand name: Vaseline) and insert it half an inch into the rectum. Hold the thermometer still and do not let go. When the thermometer beeps, remove it and check the digital reading.
• If you're taking your child's temperature orally, place the end of the thermometer under the tongue and leave it there until the thermometer beeps. Remove the thermometer and check the digital reading.
• After you're done using the thermometer, wash it in cool, soapy water