Bathhouses are back. Why you should be schvitzing.

The actor Jamie Dornan is best known for starring in the Fifty Shades of Grey films, but it was a visit to a Turkish bathhouse on New York City’s Lower East Side that left him feeling “used and abused.” Recounting his experience on the podcast Happy Sad Confused, Dornan joked that he was “treated like a piece of meat,” as he was slapped with branches (aka “sauna whisks”) and splashed with cold water, “I’m going to say it wasn’t fancy,” he joked, “but actually, it was great.”

And Dornan isn’t the only famous fan. Chicago Bath House even has a “celebrity wall of fame” that includes well-known actors, athletes and musicians who have visited the 119-year-old establishment. Or you can just turn on your TV: Nobody Wants This, Industry and the hit film Challengers all featured characters slipping into saunas or having an old-school soak this year.

The humble, no-frills bathhouse appears to be finding a new generation of schvitzers, but is it good for you? Here’s what to know before taking the plunge.

What is a bathhouse?

Unlike spas, which focus on individual services and treatments, bathhouses are all about communal experiences — including shared hot and cold pools, saunas and steam rooms. While some bathhouses have men-only or women-only hours, many are co-ed environments where patrons bring their own bathing suits.

Bathhouses have a long history in different cultures — from the ancient Romans to Turkish hammams to Russian banyas to Japanese sentos, just to name a few. But while they once served a very practical purpose (since most houses lacked indoor plumbing, people needed a place to bathe), today, they’re all about relaxing and recharging.

“The New York City area is known for being a fast-paced, stressful, pressurized and crowded environment,” Cherri Nelle Thompson, the manager of events and entertainment at Brooklyn Bathhouse, tells Yahoo Life. “In a city with limited space, most people don't even have a full-sized tub at home. Bathhouses like ours give people the chance to indulge in a customized soak, which helps you to reset, refocus and regain balance in your life.”

The benefits of bathhouses

Enduring the high temperatures of a hot tub or sauna or the frigid waters of a cold pool plunge isn’t for the faint of heart, but it does have some health benefits. And even if you don’t go for some of the tougher options, there are still some advantages to a leisurely soak.

• Physical benefits. Dr. Michael Fredericson, co-director of the Stanford Longevity Center and founder of Lifestyle Medicine at Stanford University, tells Yahoo Life that bathing in warm (around 40°C, or 104°F) water can induce vasodilation, or the widening of blood vessels to increase blood flow and lower blood pressure. Better blood circulation also aids in the delivery of oxygen and other nutrients throughout the body, which “can lead to better physical refreshment and improved skin condition,” Fredericson says. Regular sauna bathing has also been associated with reduced risks of cardiovascular diseases and improved vascular function.

• Mental health perks. Bathing in warm water and saunas can reduce anxiety and stress levels and lead to improvements in mental health, with participants in one study “reporting lower levels of stress, tension-anxiety, anger-hostility and depression-dejection after immersion bathing compared to showering,” Fredericson says. Alternating between hot and cold immersions also helps bathers reach the "totonou" state, a Japanese concept of mental and physical balance, which Fredericson says has been linked to increased brain efficiency and relaxation.

• Socialization and improved well-being. Regular whole-body immersion bathers have reported better social functioning scores, with Fredericson adding that bathing in a social setting “can also foster social interactions and a sense of community, contributing to overall quality of life.”

What to watch out for

But those warmer temperatures aren’t for everyone. Thompson says that if you have any medical concerns, you should consult a doctor before using high-heat amenities at a bathhouse — especially if you’re pregnant or have a heart condition.

Since you’re sharing space — and water — with others, you should also steer clear of bathhouses if you’re feeling unwell, have any open wounds, lesions, contagious skin conditions or fungal or bacterial infections.

Fredericson warns that there may be some health risks associated with visiting bathhouses, including “the risk of infections transmitted through sexual contact or the growth of fungi and bacteria in a hot, humid environment leading to infections.”

The dos and don’ts: How to enjoy the bathhouse safely

Ready to dive in? Before you go, brush up on some bathhouse etiquette.

• Don’t eat or drink too much — or eat too little. Thompson says that consuming too much food or alcohol can make sauna and steam room use “an uncomfortable experience,” and that the effects of alcohol are stronger when you are in extreme heat. At the same time, sauna and steam room use when you’re very hungry can also cause discomfort or dizziness.

• Do stay hydrated. Fredericson says that slips, falls and “dizziness-related incidents due to dehydration” can occur, so be sure to drink plenty of water before, during and after your visit.

• Don’t stay too long in “hot zones.” “Don't be a hero,” Thompson says. “No one needs to stay in the sauna so long that they become exhausted, overheated or light-headed. Go in for a few minutes, take a break and then go back.”

• Do “be chill” and respectful. Thompson says you should respect the fact that this is a communal, peaceful environment, by not yelling and generally being “chill.” “Enjoy,” she says. “Try to slow down and relax.”