Can You Really Sweat Out a Cold? Doctors Set the Record Straight

From hot yoga to steamy saunas, plenty of people swear by turning up the heat to beat the sniffles. Health experts are now weighing in on whether the popular trick actually helps or simply leaves you more drained.

There's nothing quite as demotivating as waking up with a stuffy nose, achy muscles, mild fatigue, and a tight chest. Once you realize you've caught a cold, the only thing on your mind is doing whatever it takes to feel better as quickly as possible.

Many people swear by "sweating out a cold," claiming they feel significantly better afterward. The approach can mean sitting in a sauna, taking a hot yoga class, or pushing through a weightlifting session. But does the method actually have any merit, and is it safe?

According to Dr. Leeja Carter, an assistant professor of sport and exercise psychology at Long Island University in Brooklyn, it's not all in your head. Exercise can give you a real boost, largely because physical activity triggers the release of mood-lifting endorphins.

That surge of endorphins can help you feel better about your body and yourself while brightening your mood, which is exactly what you need on days when you're not at your best.

Dr. Frank Esper, an infectious disease specialist at Cleveland Clinic Children's in Ohio, adds that spending time in a steam room or under a hot shower may also ease congestion in the short term, since humid air helps clear mucus from your nasal passages.

However, he notes that these effects are only temporary, because the secretions caused by your virus start building up again as soon as you step out of the heated environment. And while sweating out a cold may feel like you're flushing out "toxins," that isn't actually the case.

When you have a virus, it spreads rapidly and circulates throughout your entire body, explains Janejira Chaiyasit, DNP, an assistant professor at Columbia University School of Nursing and a nurse practitioner at its faculty practice.

A virus typically infiltrates many different kinds of cells, which makes it difficult for it to fully leave your system without medication and plenty of "work" from your body, she says, adding, "It is unlikely that you can get rid of a virus completely by raising your body temperature and sweating."

Some people assume sweating will clear up a cold because it mimics a fever, but it isn't that simple either. When you have a fever, your body is actively working to fight off an illness by increasing circulation and raising its core temperature.

"It is your body's defense mechanism, and results as your immune system is preparing to develop the necessary cells to attack," Chaiyasit says. Typically, when a fever "breaks," your body temperature returns to normal, and you may feel sweaty.

However, heating up your body and letting it cool down again, whether through a workout or time in a hot room, doesn’t have the same effect as a fever, according to Chaiyasit.

Dr. Michele Olson, a senior clinical professor of sport science at Huntingdon College in Montgomery, Alabama, agrees, pointing out that sweat serves a fairly basic function. "When sweat evaporates off your skin, your body cools. It is the primary way we reduce body temperature," she explains.

What's more, a virus's survival depends on several factors beyond temperature, including your body's pH, the type of host cell the virus latches onto, and other physical barriers. "[Temperature] is definitely an important aspect, but does not determine a virus' viability solely," Chaiyasit says.

With all that in mind, exercise can sometimes do you some good when you're under the weather. "Exercise definitely helps improve blood flow, which can help bring immune cells to the site of an infection to actively fight off a virus," Chaiyasit says.

"If most of your symptoms are above the neck (sniffling nose, sneezing, sore throat, and no fever), you can exercise within reason," Olson adds.

However, overexerting yourself can lead to dehydration and divert blood flow. As a rule of thumb, rest is your best bet when you're unwell, since it allows your body to direct its energy toward beating the infection.