When someone has a fever, like many do with disease caused by the novel coronavirus, the immediate reaction may be to take medicine to bring the fever down and start to feel better. But one doctor says when someone has an infection or virus, treating the fever may not be a good idea.

Dr. Margaret Fisher, infectious disease specialist at RWJ Barnabas Health and medical director at the Unterberg Children's Hospital at Monmouth Medical Center, said treating a fever is the worst thing a patient can do because it is one of the body's first defenses to fight off infections.

There are certain viruses and bacteria that can't survive at high body temperatures. One of the body's reasons for increasing that temperature is to give the body an advantage over the infection.

Fisher said the other reason someone wants a fever when they're sick is because in the presence of fever, the body's white cells work better. White cells are the ones that do the job of protecting the body against the germs. Our body's defenses work better when a fever is present, so don't take the fever away. This is especially important for COVID-19 patients, she said.

Many children who have fever prefer to stay in bed, away from their siblings and others in the house so they're not spreading the disease.

However, there are people who really should not have fevers, said Fisher. If someone has an illness where the fever makes the illness worse, then the fever needs to be treated. For example, in heart failure patients, the heart will actually beat much faster when there's a fever.

Fever is also not good for people who have a seizure disorder. Fisher said in those with epilepsy or convulsions, fever brings down the seizure threshold making it more likely to experience a seizure.

Fever is also harmful for people with hyperthyroidism.

Fisher said the other misconception people have is that fever will cause brain damage. She said this is false because the fever temperature would have to reach 110 degrees before there's going to be trouble with the brain and the central nervous system. She said infections would never cause a fever to soar that high. That kind of fever only happens in heat stroke patients, such as kids being left in a hot car on a scorching summer day.

Fisher said the bottom line is taking a fever away with medication might make you feel better but "it's probably also making your virus feel better and you don't want your virus to feel better."