When you or your child has a fever, you may wonder when you should see a healthcare provider.

Most fevers resolve on their own, but there are times when a fever is more concerning. For example, a newborn with a fever higher than 100.4°F (38°C) needs to be seen by a healthcare provider right away.

This article discusses when to see a healthcare provider for a fever in adults and children.

When to See a Healthcare Provider for Fever

Fever is defined as a core temperature higher than 100.4°F (38°C). A low-grade fever is a core temperature between 99.6°F to 100.3°F.

In adults, a low-grade fever isn’t usually concerning unless it comes and goes. But in babies, any fever at all can signal a serious problem.

Infants and Children

A newborn (birth to three months) that has a fever above 100.4°F needs to be seen by a healthcare provider as soon as possible.

For children (three to 12 months), call a doctor if the fever is higher than 102°F or lasts longer than 24 hours.

Other reasons to call a doctor or seek medical care for your child include:

  • Shaking or shivering (chills)Nonstop crying or crying when touchedRefusal or inability to drink enough fluidsLasting diarrhea or repeated vomitingSigns of dehydration, such as peeing less than usual, lack of tears when crying, or seeming less alertThe child has any other complaint, like earache, headache, sore throat, a rash, or pain while peeingThe child has a weakened immune system due to an organ transplant, cancer, or sickle cell diseaseThe child looks or acts very sick

Call 911 immediately or go to the nearest emergency room if any of the following occur:

  • Trouble breathingTrouble swallowing spit or fluidsPurple or blood-colored spots on the skinThe child is less responsive or non-responsiveSeizuresYou suspect there is a medical emergency for any reason

Fever in Adults

For adults, call a doctor if you have any of the following symptoms:

Do not give medication to an infant with a fever until they have been seen by a healthcare provider. Never give a child aspirin, as it is may increase the child’s risk of a rare but potentially life-threatening condition called Reye’s syndrome.

  • A temperature higher than 103°F
  • The fever lasts longer than three to five days
  • The fever does not respond to fever-reducing medication or other cool-down measures
  • The fever comes and goes, even if it is low-grade
  • You have night sweats or swollen lymph nodes
  • You have a known health condition like cancer, heart disease, or sickle-cell anemia
  • You have a cough that produces yellow, green, tan, or bloody mucus
  • You get sick with infections often
  • You recently started taking a new medicine and have no other symptoms

Seek emergency care if any of the following occur with your fever:

  • EaracheHeadacheMental confusionInability to bring your temperature down after being exposed to high heat outsideA new or strange skin rashBreathing difficulties or chest painPersistent vomiting, diarrhea, or stomach painPain or burning when urinating, possibly accompanied by stomach or back painUnusual sensitivity to lightYou are pregnantYou have recently been bitten by a tick

Fevers Aren’t Harmful in Themselves

Although people worry about fever, it’s only a symptom of an illness, not an illness itself.

If you are receiving chemotherapy and your fever lasts more than one hour, seek emergency medical care.

Most of the reasons listed above for seeking medical attention are so you can be evaluated and treated if the cause of the fever is something serious.

A fever is the body’s way of fighting off an infection and is almost never harmful.

If you’re unsure if your fever requires medical intervention, try this symptom checker for fever to help you decide.

Best Ways to Take a Temperature

There are five ways to take a person’s internal temperature, listed below from most accurate to least:

  • Rectal method: by inserting a rectal thermometer into the anus
  • Temporal method: by placing a forehead thermometer to the forehead
  • Oral method: by placing a thermometer under the tongue and closing the mouth
  • Tympanic method: by placing a thermometer in the ear
  • Axillary method: by placing a thermometer under the arm

For babies and toddlers up to three years of age, it is especially important to take the child’s temperature using the rectal method. The oral and tympanic methods are both accurate, but only when done properly.

Summary

In newborns (birth to three months), a temperature higher than 100°F warrants emergency medical care. An infant’s temperature should be taken with a rectal thermometer. If you are an adult with a fever higher than 103°F, you should also seek medical care.

While a fever itself is not harmful, it can be a sign of a serious medical condition. Call your doctor or seek medical care if you are experiencing any other concerning symptoms, or if you have another serious health condition like cancer or diabetes.

A Word From Verywell

Kids frequently have high fevers and although it may be concerning as a parent, paying attention to your child’s behavior is far more important than the number on the thermometer (with the exception of infants under 3 months old).

If your child feels better and plays after you give her a fever-reducing medicine, you probably don’t need to worry. However, if your child doesn’t have any energy, can’t keep food down, has a bad headache or stomachache, or has the fever for more than three days, be sure to call your healthcare provider.