Checking your child's temperature to determine whether he has a fever is the first step to find out if your child is either sick or in jeopardy of becoming ill. The definition of what temperature indicates fever depends on the method used to obtain the child's temperature.
Dry the armpit to follow the axillary-armpit method if child is 3 years old or younger. Place the tip of the thermometer in an armpit. Hold the elbow close to the chest for four to five minutes. Remove the thermometer and read the temperature. If the temperature reads above 99.4 degrees Fahrenheit, your child has a fever.
Place your child under the age of 3 on a flat surface, stomach down to use the alternative rectal method. Lubricate the thermometer probe with a small amount of lubricating jelly with the tip of your index finger. Insert the thermometer gently into the anal opening going no more than 1 inch deep. Hold thermometer in place for 2 minutes if using a glass thermometer or 20 seconds if using a digital thermometer. Remove the thermometer gently and read the result. If the temperature reads above 100.6 degrees Fahrenheit, your child has a fever.
Sit your child over the age of 4 in an upright position to use the ear canal method. Grasp the top of the ear between your thumb and index finger and pull slightly upward and backward to straighten the ear canal. Insert the ear probe into the ear canal and keep in place for 2 seconds. If the temperature reads above 100.6 degrees Fahrenheit, your child has a fever.
Withhold beverages 30 minutes before taking the temperature of your child 5 years or older to use the oral method. Place the thermometer on either side of the tongue, towards the back of the mouth. Hold in place for three minutes if using a glass thermometer, or 30 seconds with a digital thermometer. If the temperature reads above 99.4 degrees Fahrenheit, your child has a fever.