When someone says they’re trying to “sweat out a fever,” they usually mean they’re bundling up, raising the room temperature, or exercising to encourage sweating.
The thought is that sweating will make the fever run its course faster.
A fever is a rise in your normal body temperature. If your temperature is a degree or more over, it could simply be a short-term fluctuation. You’re generally considered to have a fever when your temperature is above 100.4°F (38°C). At 103°F (39°C), you have a high fever.
Children are considered to have a fever when their temperature is:
- above 100.4°F (38°C) with a rectal thermometer
- above 100°F (37°C) with an oral thermometer
- 99°F (37°C) measured under the armpit
Sweat is part of the body’s cooling system, so it’s not unusual to think that sweating out a fever can help. Wrapping yourself in extra clothes and blankets, taking a steam bath, and moving around are sure to make you sweat even more.
But there’s no evidence that sweating it out will help you feel better faster.
Keep in mind that a fever doesn’t necessarily require any treatment. It’s the underlying cause of the fever that you need to address.
Your body has its own built-in thermostat. Although your temperature fluctuates during the day, it stays within a fairly small range near the set point.
The set point goes up when you’re trying to fight off an infection. As your body struggles to meet that higher set point, you might get the chills.
As you make progress against the infection, your set point drops back to normal. But your body temperature is still higher, so you feel hot.
That’s when your sweat glands kick in and start producing more sweat to cool you off. This could mean your fever is breaking and you’re on the road to recovery. But making yourself sweat more doesn’t treat the fever or its cause.
Because so many things can cause a fever, the fact that it’s breaking doesn’t mean that you’re out of the woods.
Fever can return after you’ve gone through a period of sweating and after you’ve had a normal temperature reading. In the case of COVID-19, for example, you may feel better for a few days after your fever breaks, but symptoms can return.
It’s common to sweat when you’re running a fever. Fever itself isn’t an illness — it’s a response to infection, inflammation, or disease. It’s a sign that your body is fighting off an illness, but it doesn’t necessarily require treatment.
Making yourself sweat more isn’t likely to help you recover, though it’s not necessarily unhealthy. Much depends on the cause.
According to a
- fluid loss and dehydration
- metabolic demands, meaning the body requires more energy and resources to raise its temperature
- dysregulation of body temperature, making it difficult for you to maintain the correct temperature when exercising
Fever causes a few detrimental effects on the musculoskeletal system, such as decreased strength, endurance, and fatigue. The researchers concluded that engaging in strenuous exercise with a fever can worsen your illness.
Some sweating with a fever is to be expected. But if you try to sweat more by exercising or cranking up the room temperature, there are some potential side effects to be aware of:
- Higher fever. If your fever is already high, sweating it out might actually raise your temperature. You lose heat through your skin, so it might be better to remove excess blankets and clothing once you’re over the chills.
- Fluid loss. Even if you’re just lying in bed, fever-induced sweating can deplete you of fluids. That’s why the standard advice for fever is to drink plenty of fluids. Trying to sweating more can raise the risk of dehydration.
- Exhaustion. Fighting off infection and having a higher body temperature can take a lot out of you. Exercising to increase sweating might make you feel weaker.
A low-grade fever doesn’t always warrant a trip to the doctor. But a fever can be an indicator of serious illness, so you’ll want to take a few things into account when determining if it’s time to seek medical attention.
Infants and toddlers
An unexplained fever should be a cause for concern. Call your doctor when:
- a baby 3 months or younger has a rectal temperature of 100.4°F (38°C) or higher
- a baby between 3 and 6 months has a rectal temperature up to 102°F (39°C) accompanied by irritability or lethargy
- a baby between 3 and 6 months has a rectal temperature above 102°F (39°C)
- a toddler between 6 and 24 months has a temperature above 102°F (39°C) with other symptoms, such as cough or diarrhea
- a toddler between 6 and 24 months has a rectal temperature above 102°F (39°C) lasting more than 1 day, even if there are no other symptoms
You don’t have to be too concerned if your child has a low fever and is drinking fluids, playing, and responding normally. But you should call the doctor when their fever has lasted more than 3 days or is accompanied by:
- listlessness or poor eye contact
A fever after being left in a hot car is a medical emergency. Call 9-1-1 immediately.
Generally speaking, you should call a doctor for a fever of 103°F (39°C) or higher and if you have:
- abdominal pain
- chest pain
- convulsions or seizures
- coughing up blood
- light sensitivity
- mental confusion
- pain when urinating
- severe headache
- shortness of breath
- stiff neck or pain when you tilt your head forward
- unusual skin rash
Call 9-1-1 if you or someone else has a fever, chest pain, and trouble breathing. Be sure to report any known exposure to COVID-19.
At any age, fever can be due to:
- heat exhaustion
- inflammatory conditions such as rheumatoid arthritis
- malignant tumors
- certain medications, including some antibiotics and medications that treat high blood pressure or seizures
- some immunizations
You should also consider your potential exposure to infectious diseases. This includes a variety of viral and bacterial infections, some of which you could unknowingly be spreading to others, such as:
What to do if you think you have covid-19?
If you think you may have COVID-19, or have been exposed to it, isolate yourself from others. Don’t go directly to a doctor’s office or hospital. Call first.
A doctor may be able to conduct a phone or video visit. If you need hospitalization, arrangements must be made in advance to prevent exposing others.
After having a fever and the chills for some time, it could be that you got in the habit of overdressing or keeping the room too warm. It’s also possible that you’ve increased your physical activity too quickly and need a few more days to regain strength.
Depending on the fever’s cause and how physically active you are, it shouldn’t be too long before you get back to your normal level of sweating.
Some reasons you might develop night sweats include:
- certain medications, such as pain relievers, steroids, and antidepressants
- low blood sugar (hypoglycemia)
If you continue to sweat more than normal or you’re concerned that you’re not fully recovered, see a doctor.
Fever and sweat tend to go together already. But purposely making yourself sweat more isn’t likely to end your fever sooner. You can develop a fever for a variety of reasons, so it’s important to be aware of your symptoms and call a doctor with any concerns.