Fever 101: The why, how and what to do for fevers in children


“I don’t feel so good,” your child groans. You put a hand to your child’s forehead, and sure enough, it’s warm to the touch. Fever strikes again!

A fever is not an illness itself – it is actually a sign that the body is fighting off an infection. And while fevers may cause your child discomfort, they are generally not a serious health concern. Fevers usually go away on their own after a few days.

High, medium, low: When is it fever? Though 98.6F is considered a “normal” body temperature, our temperatures actually fluctuate throughout the day. But anything above 100.3F is considered a fever.

Normal body temperature is typically highest in the evening, says Carlos Lerner, MD, UCLA pediatrician. So when your child is sick, that natural increase in body temperature, plus the elevated temperature caused by the fever, means your child may be most miserable during evening and nighttime hours.

“Everything hurts” Common symptoms of fever include:

  • Temperature on the thermometer is higher than normal
  • Hot, dry skin
  • Sweating, shivering and/or chills
  • Weakness
  • Muscle aches
  • Loss of appetite
  • Headache
  • Dehydration

Three ways to take your child’s temperature Even if you can tell by touch that your child has a fever, it’s a good idea to take his or her temperature, so you have an accurate reading. This is especially important in younger children, because a high temperature may warrant a call to your doctor.

There are three commonly used thermometers you can use to get an accurate temperature. Most should give you a reading within 10 seconds to two minutes.

  • Rectal: This is best for infants and has a high level of accuracy. Insert the flexible tip of the thermometer into your child’s rectum, but no further than an inch. Be sure to use this thermometer for rectal temps only. Keep a separate one around for taking temperature by mouth.
  • Oral: When children are a little older (around age 4), they can hold the tip of the thermometer under their tongues, with their mouths closed.
  • Ear: Insert the thermometer into your child’s ear. This is best for babies 6 months and older because the ear canals in younger babies may be too narrow.

Treating a fever You can’t “cure” a fever, but these steps may make your child more comfortable:

  • Dressing lightly
  • Drinking plenty of liquids
  • Taking a lukewarm bath if they have the chills
  • Placing a cold washcloth on the forehead or wrists
  • Taking medicine:
    • For children older than 3 months with a temperature of 102F or more, you can give acetaminophen (Tylenol).
    • For children older than 6 months, you can also give ibuprofen (Motrin®).
    • If your child is older than 3 months with a temperature below 102F, he/she does not typically require medication.

A child can return to daycare or school after being fever-free for 24 hours.

When a fever is serious Though you usually do not need to schedule a doctor’s visit at the first sign of fever, you should call your doctor if your child has these symptoms:

  • A temperature of 104F or higher
  • Fever that lasts more than three days (or more than 24 hours for children under age 2)
  • Seizure, irregular breathing, stiff neck, vomiting or not eating/drinking
  • Fever 100.4F or higher among children younger than 3 months
  • Temperature above 102.5F for children between the ages of 3 and 6 months

These may be signs of a more serious illness and should be addressed immediately.

For your child’s fevers, and any other aches and pains of childhood, make an appointment with the expert pediatricians at Mattel Children’s Hospital UCLA.