A Blog from Your Kaiser Permanente Pediatricians in Northern California

child in bed with a fever and thermometer

Your Child Has a Fever. When to Call the Doctor.

You’re sitting with your sick child, looking at a thermometer, and wondering, “How high is too high?”

Does this sound familiar? Most of us have been there – even me. And I know that fever is just a symptom that can actually play a positive role in fighting infections – and it’s rarely serious! Yet I still worry when my kids have a fever.

Fever isn’t always a bad thing. That’s right – fever can even be helpful or be “one of the good guys!” By increasing the body’s temperature, the immune system is working to kill off some of the virus that’s making your child ill. Because of that, you usually don’t need to worry too much, and you definitely don’t need to treat every fever your child gets!

What is a “fever?” Normal body temperature is usually 98.6ºF but can vary about a degree on either side of that. Fever is defined as being 100.4ºF or more when measured properly.

Most kids will be less active when they have a fever. To figure out how ill your child is it’s important to think less about the fever and more about how they seem to be acting. It’s reassuring if they return to being active or playful when their fever is down. If they don’t, it’s time to call your doctor.

Not all kids with fevers need to be seen by a doctor. Many can be treated at home by taking anti-fever medicine, drinking extra fluids, taking warm baths, sponging, avoiding over-bundling, and keeping rooms comfortably cool.

Call your doctor if:

Your baby is younger that 3 months and has a temperature 100.4ºF or more. It’s most accurate to measure temperature rectally at this age with a digital thermometer. Any baby who won’t eat, seems listless, or has a bulging soft spot should be seen by a doctor.

Your child of any age:

  • Is irritable or crying constantly
  • Seems confused or extremely sleepy
  • Lacks energy or is limp or listless
  • Has a prolonged, deep cough, trouble breathing, wheezing or tightness in the chest
  • Is vomiting or has diarrhea
  • Shows signs of being dehydrated (refuses to drink; has a dry mouth, dark urine or is urinating less that 4 times in 24 hours)
  • Has a stiff neck
  • Has severe pain (headache, joint pain, ear pain, bad sore throat or pain when urinating)
  • Has a rash

Also talk with your doctor if your child’s fever lasts for more that 3 days, doesn’t seem to be improving, or if the fever returns after a period of time when they seemed better.

If your child doesn’t have the warning signs listed above, sending an email to or scheduling a video visit with your doctor can be a great way to be reassured.

You’re probably still going to worry the next time your child has a fever. As a mom of 3 kids who’ve had their share of fevers, I probably will too! But now at least you have a clear guide for when to talk with your doctor about the fever.

Find more resources for parents:

My Doctor Online
Fever in Children
Recommended Doses of Acetaminophen and Ibuprofen

American Academy of Pediatrics
Fever Without Fear: Information for Parent

This article was originally published on January 3, 2019

Disclaimer: If you have an emergency medical condition, call 911 or go to the nearest hospital. An emergency medical condition is any of the following: (1) a medical condition that manifests itself by acute symptoms of sufficient severity (including severe pain) such that you could reasonably expect the absence of immediate medical attention to result in serious jeopardy to your health or body functions or organs; (2) active labor when there isn't enough time for safe transfer to a Plan hospital (or designated hospital) before delivery, or if transfer poses a threat to your (or your unborn child's) health and safety, or (3) a mental disorder that manifests itself by acute symptoms of sufficient severity such that either you are an immediate danger to yourself or others, or you are not immediately able to provide for, or use, food, shelter, or clothing, due to the mental disorder. This information is not intended to diagnose health problems or to take the place of specific medical advice or care you receive from your physician or other health care professional. If you have persistent health problems, or if you have additional questions, please consult with your doctor. If you have questions or need more information about your medication, please speak to your pharmacist. Kaiser Permanente does not endorse the medications or products mentioned. Any trade names listed are for easy identification only.