If your child feels warm, looks flushed, is sweating or shivering, or has flu symptoms, you might suspect fever. Using a thermometer is the only sure way to know if a fever is present.

Some parents are all thumbs when it comes to taking a temperature. A basic digital version may be the most practical and reliable way to determine if your child has a fever. Mercury thermometers should not be in your medicine cabinet; the silver liquid inside is dangerous if the thermometer breaks.

Use a digital thermometer to take a rectal (in the bottom), oral (in the mouth) or axillary (under the arm) temperature. A tympanic (ear) thermometer, which is more expensive, is another option. Other methods are available but are not recommended by the American Academy of Pediatrics (AAP) at this time.

Temperatures taken rectally or orally are more accurate than those obtained using the axillary or tympanic methods. If your child is younger than 3 years old, a rectal temperature gives the best reading. At around 4 or 5, you can feel comfortable taking a temperature by mouth.

A normal temperature for a child may range from 97 degrees Fahrenheit (F) to 100.4 degrees F. In general, the AAP considers anything over 100.4 degrees F to be a possible fever.

  • Clean the end of the thermometer with rubbing alcohol or soap and water; rinse in lukewarm water and dry. Apply a small amount of lubricant, such as petroleum jelly, on the end.

  • Place your child tummy down across your lap. Hold the child by placing your palm against his lower back. Or, place the child face up and bend his legs to the chest. Rest your free hand against the back of the thighs.

  • With the other hand, turn the thermometer on, and insert it ½ to 1 inch into the anal opening (not too far). Hold the thermometer in place loosely with two fingers, keeping your hand cupped around your child’s bottom. In about a minute, when you hear the beep, remove it and check the reading.

  • Re-clean. Be sure the thermometer is labeled so it’s not accidentally used in the mouth.

  • Wait 15 minutes after the child has been eating or drinking before taking a temperature.

  • Clean thermometer. Turn the thermometer on, and place the tip under the tongue toward the back of the child’s mouth. Hold in place for a minute until you hear a beep.

  • Turn on the thermometer, and place the small end in your child’s armpit (thermometer should touch skin, not clothing).

  • Gently hold the arm in place until the thermometer beeps.

  • The AAP advises against using this method for infants younger than 3 months. While a tympanic thermometer provides speedy results, the device needs to be inserted at the right angle in a child’s ear to provide an accurate reading. Don’t use these devices right after a child has been swimming or bathing of if ear pain is present.

  • Place a clean cover on the cone-shaped end.

  • Pull the ear backward slightly, and gently place the thermometer in the ear canal. Try to aim the probe toward the child’s eye on the opposite side of the head.

  • Turn on the thermometer; remove after it beeps.