Women's Health November 10, 2026 0 Comments

Unlock the Surprising Immune Boost Hidden in This Unexpected Bathing Ritual—You’ll Never Look at Your Shower the Same!

Ever wonder if sitting in a sauna is more than just a luxurious way to sweat out last night’s sins? Turns out, spending a solid 30 minutes roasting in that steamy heat might actually launch a blitzkrieg of immune cells your body throws into battle against invaders. Yeah, it’s like your white blood cells are pumped up and ready to roll—just from one session. But before you book every sauna day of the week, hold up: scientists are still scratching their heads, figuring out exactly what this flood of immune warriors means for your long-term health. So, could this be your new secret weapon for a tougher immune system, or just a hot way to relax? Let’s break down the sweat science behind sauna sessions and why this isn’t just another wellness fad. LEARN MORE

4 min read

New research suggests 30 minutes in a sauna could trigger a unique immune cell response.
Just one sauna session can spark a flood of white blood cells.
Researchers are still exploring what happens after these white blood cell release.

Sitting in a sauna is a nice way to unwind, whether you’re starting your day or coming down post-workout. But while it can feel good to lounge in the heat to decompress, research suggests you might be doing your immune system a solid in the process, too.

The study, which was published in the journal Temperature, found that hanging (or ‘bathing,’ as it’s called) in the sauna for 30 minutes sparks a unique chain reaction in the body that could support your health. Scientists haven’t quite figured out what these changes mean when it comes to measurable impact on immunity, but doctors say this is definitely one more thing to mull over while you’re getting your sauna on. Here’s why.

Meet the experts: Jari Laukkanen, MD, PhD, study co-author and professor at the University of Eastern Finland; Eric Ascher, DO, family medicine physician at Northwell’s Lenox Hill Hospital; and Joseph J. Ciotola, MD, an orthopedic surgeon at Baltimore’s Mercy Medical Center

What did the study find?

For the study, researchers recruited 51 adults with an average age of 50. Scientists took blood samples before asking participants to sit in a 163-degree sauna for 30 minutes. The participants gave blood samples again right after the sauna session and again 30 minutes later.

The researchers found that there was a temporary increase in every type of circulating white blood cell they measured, including immune cells called neutrophils and lymphocytes. Neutrophils are usually the first defenders to respond to an infection and lymphocytes recognize specific threats, make antibodies, and help coordinate immune responses. The increase only lasted for 30 minutes—the neutrophil and lymphocyte counts returned to baseline after that.

“We have studied sauna bathing and cardiovascular health for many years, and our previous studies have shown interesting associations with better health outcomes,” says Jari Laukkanen, MD, PhD, study co-author and professor at the University of Eastern Finland. “We wanted to understand more about the biological mechanisms behind these findings, including possible effects on the immune system.”

Why might sitting in a sauna support your immune system?

Again, the researchers simply found that this jump in certain white blood cells happens when someone sits in a sauna—they didn’t figure out why it happens or what it means. Still, experts have a few theories.

One is that sauna bathing presents a sudden physical challenge for the body, according to Eric Ascher, DO, a family medicine physician at Northwell’s Lenox Hill Hospital. “This heat stress wakes up your nervous system, causing white blood cells stored in different parts of your body to rush into your bloodstream,” he says.

This is similar to what happens in the body when you do a cold plunge, says Joseph J. Ciotola, MD, an orthopedic surgeon at Baltimore’s Mercy Medical Center. “It’s just hormetic stress,” he adds, referring to the process where short stressors can trigger a positive adaptive response in the body and make you stronger.

The release of these immune cells is also similar to what happens during physical exercise, Laukkanen says.

As for what this means for the body, that’s still being explored. “White blood cells are important for immune defense and surveillance,” Laukkanen says. “Their temporary mobilization may help the body respond to physiological challenges.”

But Laukkanen also says that it’s not clear yet what this means for immune health. “Our study measured acute responses after one sauna session, and we cannot yet say whether these changes improve long-term immunity or reduce the risk of infections,” he says. “More research is needed.”

What other benefits come from sitting in a sauna?

You do more than just sweat in a sauna. “Saunas make your heart beat faster, and your blood vessels open up, which is very similar to the benefits you get from taking a brisk walk or going for a light run,” Ascher says. “Because of this, regular sauna use has been linked to lower blood pressure, a healthier heart, and a lower risk of getting certain long-term diseases.” (Still, he stresses that there’s no data now to suggest that sauna use will replace the need for medication or exercise.)

Sauna use can also help people relax, recover from stress, and support overall well-being, Laukkanen says. “Sauna can be a pleasant part of a healthy lifestyle, alongside regular physical activity,” he adds.

Of course, not everyone should hop in the sauna. “Because the intense heat puts a lot of stress on your heart and body, anyone with serious heart problems, very low blood pressure, or severe dizziness should stay out of saunas,” Ascher says. Pregnant women and older adults may also want to steer clear.

But if you already like hanging in the sauna, it’s nice to know you might be doing your immune system a solid while you kick back and enjoy.

Carina Hsieh, MPH, is the deputy features editor of Women’s Health. She has more than a decade’s worth of experience working in media and has covered everything from beauty, fashion, travel, lifestyle, pets, to health.

She began her career as an intern in the fashion closet at Cosmopolitan where she worked her way up to Senior Sex & Relationships Editor. While covering women’s health there, she discovered her passion for health service journalism and took a break to get her Masters in Public Health. Post-grad school, she worked as a freelance writer and as The Daily Beast’s first Beauty, Health, and Wellness Reporter.

Carina is an alum of the Fashion Institute of Technology and the Yale School of Public Health. She and her French Bulldog, Bao Bao, split their time between Brooklyn and Connecticut. She enjoys reformer Pilates, (slow) running, and smelling the fancy toiletries in boutique fitness class locker rooms.