By Melissa Erickson

For parents, especially new parents, a child’s fever can be a frightening thing. When is a fever cause for concern, and when is it just part of a natural childhood illness?

Every child will eventually run a fever, which is simply a rise in a child’s body temperature, said Dr. Rupal Gupta, a pediatrician with Nemours and medical editor for

“The fever is not generally dangerous in itself, but it can indicate an underlying problem. It’s important to identify the cause” of the fever, Gupta said. Infections often cause fever, but fever can also be present in a child overheated due to sports activity or overdressing, she said.

What is too high?

A fever is defined as a temperature over 100.4 degrees Fahrenheit, Gupta said. Normal body temperature is 98.6 degrees, but body temperature can vary by a degree or two over the course of the day, and by a child’s age and activity level.

“My most frequent calls are from worried parents who want to know how high is too high of a fever. What many parents don’t realize is that often, fevers are their child’s friend,” said Dr. Hannah Chow-Johnson, Loyola University Health System pediatrician and assistant professor in the department of pediatrics at Loyola University Chicago Stritch School of Medicine.

“Fevers can actually help your child recover more quickly, especially if he or she is battling a viral illness,” said Chow-Johnson. “I often wish thermometers had a gauge that read either ‘fever’ or ‘no fever.’ That would definitely help parents who worry if their child has a fever that’s too high.”

There are a variety of thermometers to gauge a child’s temperature. For infants younger than 3 months, it’s important to use a rectal thermometer to get the most accurate measurement, Gupta said. Digital oral thermometers are fast and accurate and can be used for older children who can sit still with a thermometer in their mouths for 30 seconds. Temple and ear thermometers and forehead strips are some of the other types.

When to call a doctor

For infants three months and younger, call the doctor for a temperature of 100.4 or higher.

For older children, “look at the fever in the context of the whole child,” Gupta said. If a child is running a fever, but otherwise his behavior is normal, you probably don’t need to be concerned.

On the other hand, if a child with a fever is just not himself, not eating and drinking, not going to the bathroom, not alert, not playing as they normally would, it’s time to make a doctor’s appointment, Gupta said.

Also call a doctor:

– If a fever lasts longer than five days.

– If a fever is higher than 104 degrees.

– If the fever doesn’t come down after taking fever reducers.

– If there is no clear source for the child’s fever (no cough, runny nose or known pain) and the fever has lasted for two to three days.

Fevers are not pleasant for kids. They can make them unhappy and fussy. They also force them to slow down, rest and sleep more, which are all necessary for a child to recover from an illness.

Your goal should be your child’s comfort, not reducing the fever, Chow-Johnson said. Be generous with fluids, ice chips and ice pops. Dress your child in light clothing and give tepid baths to help cool him or her down.

Avoid using rubbing alcohol, as this can be absorbed into the skin. Give fever reducers only if your child feels uncomfortable, not solely to reduce the temperature. And don’t alternate fever-reducing medications, as this could lead to overdosing or giving medication your child doesn’t need.