Fever Basics, and How to Take Your Child's Temperature

December 21, 2017 Lisa Hoang, MD


Every parent worries when their child's temperature goes up. A warm forehead raises fears of a potentially serious illness. But it's not necessarily the case. Although it can be scary when your child gets a fever, the fever itself is not harmful – and may even be beneficial.

“Fever is a symptom, not a disease,“ says Lisa Hoang, MD, a board-certified pediatrician at St. Joseph Heritage Medical Group. “Most experts agree that fever is a normal, healthy defense against infections. In most cases, fever indicates a minor illness. To determine how serious the illness is, parents and their physicians must look at accompanying symptoms.”

When should you call the doctor about your child's fever?

Parents need to be extra cautious when their baby's or toddler's temperature rises. Babies less than 3 months old should be seen by a doctor any time their rectal temperature exceeds 100.4 F, because they can become seriously ill very quickly. Babies aged 3 to 6 months who have a fever of 100-102 F that is accompanied by significant discomfort or lethargy should also be seen by a doctor. Parents should also pay careful attention to the length of time the fever lasts. For all toddlers under age 2, call the doctor if the fever lasts more than one day; for small children over the age of 2, they should be seen if the fevers are more than three days.

Other symptoms that may be cause for concern when accompanied by fever include: Lethargy, sore throat, severe headache, cough, trouble breathing, poor appetite, vomiting, earache, stiff neck, rash, pain with urination or diarrhea. When your febrile child has any of these additional symptoms, you should seek medical care.

A minor viral illness will usually cause a fever that goes away in 3 to 4 days. Although a child may feel fussy and uncomfortable with a high fever, fevers rarely cause medical problems in themselves. It is not unusual for preschoolers to get 6-10 viral infections in a single year, and each one may cause a new fever, but a normal healthy child should get over these viral infections relatively easily.

When should you take a feverish child to the hospital?

“How the child looks is more important than the number itself. Even if the fever is not high but your child is lethargic, not breathing well, extremely uncomfortable or in pain, you should have them evaluated. Babies under 3 months old should be evaluated when they have a fever," says Dr. Hoang. "High fevers can sometimes cause seizures called febrile seizures. If your child has a seizure or has a pre-existing medical condition such as a weakened immune system, there should, of course, be no hesitation about taking him or her to the hospital right away.”

How do you take your child’s temperature?
If your child is older, you may use an oral thermometer that you place under the tongue. For toddlers and infants, you should use one that you place under their arm. If there is any concern or question about the accuracy of an infant’s temperature under the arm, the most accurate temperature is one that is done rectally. A fever is 100.4 or above.

There are also non-emergency causes of fever:

  • Viral infections such as a minor cold or flu
  • Immunizations

“When children have few symptoms and the fever seems mild, there is probably no need to worry,” adds Dr. Hoang. “But when something seems really wrong, they should trust their gut and contact a medical professional. “

“Fevers can be uncomfortable, so acetaminophen or ibuprofen may help the child feel a little better. However, for children under two years old, parents should discuss the dosages with their doctor,” advises Dr. Hoang. You can also help them feel more comfortable without using medicine. “Try giving them a lukewarm tub bath or sponge bath, to help cool the skin, or place a damp washcloth on the child’s forehead. Keep your child well hydrated. You can also remove a layer of clothing to keep your child comfortable.”

If your child has a fever but you feel that it isn't an emergency, consider taking them to an urgent care, where doctors can treat problems that are not life-threatening. If urgent intervention is truly required, they can help manage the next steps in your child’s care. Click here for a directory of St. Joseph Health urgent care locations in Southern California For St. Joseph Health urgent care locations in Northern California, click here for the Sonoma area and click here for Napa..

How have you successfully handled childhood fever? Share your story and tips here.

This information is not intended as a substitute for professional medical care. Always follow your health care professional's instructions.


Previous Article
Hot Tea Swirl-Ins That Are Better Than Sugar
Hot Tea Swirl-Ins That Are Better Than Sugar

Try these hot tea swirl-ins that aren't sugar

Next Article
How to Treat Colds at Any Age
How to Treat Colds at Any Age

Cold treatment and prevention tips for all ages