Letting a fever run to fight coronavirus could be risky

If you’re a mostly healthy person who contracts the coronavirus, will letting your fever run high help get rid of it?

That’s what a post shared on Facebook suggests. It says: 

"Passing along corona advise from a retired respiratory therapist" for "the otherwise generally healthy population." 

It lists eight recommendations, starting with:

"For people experiencing mild to moderate respiratory symptoms with or without a COVID-19 diagnosis. … Only high temperatures kill a virus, so let your fever run high. … Use common sense and don't let fever go over 103 or 104 if you got the guts."

The final recommendation is: "If your still dying go to ER." (Yes, it says, "advise" instead of "advice" and "your" instead of "you’re" in the post.) 

The post was flagged as part of Facebook’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Facebook.)

We’ll first note that it’s best to take your medical advice from health care professionals, not from random Facebook posts.

Doctors say it’s true that a high temperature can help the body fight off a virus, but not enough is known about the new coronavirus to support the post’s advice, and running a high fever could be dangerous.

A fever means you have a temperature of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher, according to the federal Centers for Disease Control and Prevention. 

Fevers are a common sign of illness, but they also play a key role in fighting infections.

Generally speaking, a fever is "basically a symptom of your immune system trying to fight the virus" Richard Watanabe, a professor of preventive medicine at the University of Southern California, told PolitiFact. "The higher temperature does make it more difficult for some viruses to survive."

The Mayo Clinic offers general tips — for otherwise healthy people and not specifically for coronavirus — on deciding whether to treat a fever or let it run its course. For example, for adults with a temperature above 102, Mayo recommends acetaminophen (Tylenol and other brands), ibuprofen (Advil, Motrin IB) or aspirin. 

But it says treatment decisions also depend on age, medical history, other symptoms and other factors,  not just temperature.

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Fever, along with cough and shortness of breath, is among the symptoms of COVID-19. If you have symptoms and think you have been exposed to COVID-19, call your healthcare provider, the CDC advises.

CDC’s Self-Checker tool can help you make decisions about seeking medical care. Mayo Clinic also offers a tool that helps you decide on seeking medical care and whether you need a COVID-19 test.

If you’ll be treating COVID-19 symptoms at home, get enough rest, stay well-hydrated, and take medications to relieve fever and aches and pains, Harvard Medical School says. 

For fever, aches and pains, the school recommends acetaminophen. But if you are taking any combination cold or flu medicine, keep track of all the ingredients and doses, and make sure not to exceed a total of 3,000 milligrams of acetaminophen per day.

Mayo Clinic recommends rest and fluids, as well as cough medication, and pain relievers such as acetaminophen or ibuprofen. 

There have been some claims that using ibuprofen to treat coronavirus symptoms is risky. We found that some medical experts believe ibuprofen’s anti-inflammatory properties could damp the immune system’s ability to fight off COVID-19. But experts say this is just a theory and that there’s no scientific evidence that links ibuprofen and other anti-inflammatory medications with COVID-19 complications.

That said, there is no rule that says you need to lower a fever with over-the-counter medication if you’re feeling only mild symptoms and are not uncomfortable, Consumer Reports says in an article on COVID-19 and fevers. It lists a cold compress for sweating and blankets for chills, along with rest and liquids, as alternatives. 

The article says there is an argument for letting a fever run its course, because lowering a fever with medication might suppress your body’s ability to fend off illness, "but if your fever is running at or above 103 degrees, you should call a doctor. A high fever could lead to a seizure or brain damage."

Dr. Myron Cohen, professor of medicine, microbiology and immunology, and epidemiology at the University of North Carolina and director of its Institute for Global Health & Infectious Diseases, told PolitiFact that while there is research suggesting that fever can defend against infection, "it is extremely difficult to relate the magnitude of fever to the severity of infection, or to demonstrate the benefits of fever for any given microorganism," including the COVID-19 virus. 

The body’s immune response is the most important factor in killing the virus, said Dr. Wilbur Chen, an infectious disease physician-scientist at the University of Maryland. "The fever response is just one of the symptoms that are experienced when the immune response is revved up when fighting the virus. It is like what smoke is to fire—the point is that you are not focusing your concern on putting out the smoke; you want to put out the fire," he said.

Said Watanabe: "The caveat here is how heat-tolerant is COVID-19? That is, as far as I am aware, an unanswered question. There are viruses that are relatively heat-tolerant, so your body’s fever defense may not be effective."

A Facebook post advises that generally healthy people "experiencing mild to moderate respiratory symptoms with or without a COVID-19 diagnosis" should "let your fever run high" to kill a coronavirus.

Generally speaking, a fever under 103 degrees doesn’t necessarily need treatment. But that depends on other factors, such as age, underlying health conditions and other symptoms. 

Higher temperatures and persistent fevers are dangerous. And it isn’t yet known whether a fever might help the body fight the novel coronavirus, as it does other viruses.

The advice on letting a fever run high to fight the coronavirus, even with generally healthy people and mild to moderate respiratory symptoms, is too broad. We rate it Mostly False.