What’s considered a fever and when to see a doctor

Humans – like all mammals – are warm-blooded, meaning our bodies stay warm, or at a fairly consistent temperature, even when the temperature of our surroundings change.

For most of us, our bodies tend to hover between 97 and 99 degrees Fahrenheit. But in certain circumstances, our body temperate rises, resulting in a fever.

“Your body’s immune system creates a fever to fight off infection,” said Sarah Joseph, MD. As an internal medicine and pediatrics specialist, Dr. Joseph treats children and adults of all ages for a wide range of illnesses.

Low-grade fever

The medical community generally defines a fever as a body temperature above 100.4 degrees Fahrenheit. A body temp between 100.4 and 102.2 degree is usually considered a low-grade fever.

“If the temperature is not high, it doesn’t necessarily need to be treated with medication,” Dr. Joseph said.

A low-grade fever usually doesn’t require treatment, unless the fever is occurring in a very young infant, or if it’s accompanied by other worrisome symptoms, such as confusion or the inability to eat or drink without vomiting.

To bring down a fever without medication, Dr. Joseph suggests wearing minimal clothing or bathing in lukewarm or cool water. You should also be sure to drink plenty of fluids to keep your body hydrated.

And keep in mind that even a mild fever could be a sign of a contagious illness. Washing your hands and covering your cough are always good practices.

“In the age of COVID-19, one of the things people should keep in mind is that if they are having any kind of fever that is persisting, they should probably go get tested,” Dr. Joseph said.

Not sure whether you need a test or where to get tested? Use our digital assistant, Clare, located in the lower right corner of the OSF HealthCare website.

High fever

When body temperature rises above 102.2 degrees, it can be a sign of a more serious infection.

Most fevers will resolve in a few days, but Dr. Joseph says some circumstances could be reason to see a provider, either in a primary care office or urgent care clinic.

Consider seeing a doctor if:

• Fever lasts longer than three to five days
• Fever doesn’t respond to fever-reducing medications, such as acetaminophen or ibuprofen (Tylenol or Advil)
• Other symptoms include confusion, neck stiffness or sensitivity to light

“Another reason to seek medical attention is if you don’t feel right about how things are going,” Dr. Joseph said.

Rarely, a fever could be a sign of a medical emergency.

Call 911 or go directly to an emergency room if you have a fever and any of the following symptoms:

Last Updated: February 10, 2022