Each winter, cold and flu season reaches its peak. That leaves a lot of people dealing with coughing, sneezing and fevers.
People often take fever reducers to lower their body temperature when they’re sick. But VERIFY reader Richard asked us if fevers actually help kill viruses or bacterial infections if you have a cold or the flu.
THE QUESTION
Do fevers help the body kill viruses and bacteria?
THE SOURCES
- University of Rochester Medical Center
- Cleveland Clinic
- Penn Medicine
- MedlinePlus
- Boston Children’s Hospital
THE ANSWER
Yes, fevers do help the body kill viruses and bacteria.
WHAT WE FOUND
The human body uses fevers as part of its defense system against viral and bacterial infections. That means mild fevers, while uncomfortable, can be helpful in fighting a cold or the flu. However, severe fevers can be dangerous and even fatal.
Body temperature varies from person-to-person and can change throughout the day, but a normal range is typically between 97.5 and 99.5 degrees Fahrenheit, according to the University of Rochester Medical Center.
There aren’t any strict guidelines on what the minimum temperature for a fever is because of this variability, the Cleveland Clinic says. However, healthcare providers generally say that a temperature of 100.4 degrees Fahrenheit measured by mouth is a fever. Penn Medicine goes a little lower; it says a temperature above 99.5 is a fever.
Fevers are an increase in your normal body temperature. Most bacterial infections and viruses do well when your body is at its normal temperature, says MedlinePlus. A fever, therefore, makes it harder for those germs to survive.
“When you get a bacterial or viral infection, your body’s defenses kick in and your temperature rises as your immune system tries to kill off the invading germs,” the University of Rochester Medical Center says. “The higher body temperatures make your body a far more hostile environment to those viruses or bacteria, making it harder for them to survive.”
Fevers also activate the body’s immune system, according to MedlinePlus. Fevers stimulate the release of chemicals, cells and antibodies made to fight germs, according to Boston Children’s Hospital.
If a fever is mild, which Cleveland Clinic says is less than 101 degrees Fahrenheit, you usually don’t need to treat it with medication. Instead, just drink plenty of fluids and get plenty of rest. Cleveland Clinic says you can try to break a fever with medicine like ibuprofen if you’re feeling uncomfortable and your fever is higher than 101 degrees.
When fevers become dangerous
While higher fevers don’t necessarily mean you’re facing a more serious health issue, they do become more dangerous the higher they are. Cleveland Clinic says untreated fevers above 105.8 degrees Fahrenheit can cause organs to malfunction. Fevers over 107.6 degrees Fahrenheit can damage the brain, Penn Medicine says.
Medical experts therefore recommend you see a doctor about your fever well before that point. As an adult, if your fever is over 103 degrees Fahrenheit and isn’t responding to medication, it’s time to talk to your doctor.
For children, medical experts say to seek help if their fever is over 104 degrees Fahrenheit. Boston Children’s Hospital says it is considered a medical emergency if your child reaches 105 degrees Fahrenheit.
The threshold is lower for younger children. If a baby between 3 months and 2 years old has a fever of at least 102 degrees, you should talk to their doctor, Boston Children’s Hospital recommends.
If a baby under 3 months of age has any fever at all, Cleveland Clinic recommends taking them to the emergency room because their immune system hasn’t developed fully yet, and they could have a serious infection.
Moderate fevers can be dangerous to adults with lung or heart disorders because they can cause heart and breathing rates to increase, Cleveland Clinic says. And if any fever lasts too long — Cleveland Clinic says more than four days in an adult and more than five days in children — then you should talk to a healthcare provider.