Saunas are making a resurgence in Colorado. Here’s why.

It’s so hot right now: sitting in a small, steamy room, sweating out the aches of life.

It’s also very, very cool: submerging your overheated self into a tub of near-freezing water complete with tiny icebergs.

Welcome to the world of sauna, an ancient practice that’s resurging as a wellness tool and workout-recovery technique. Thanks to the fast-moving trend factory that is social media, new generations are starting to catch on to the old customs.

Native American sweat lodges, Turkish hammams and Finnish saunas all serve as health-focused community spaces, steeped in ritual. Modern “sauna studios,” like CYL Sauna and Perspire, use infrared light to get sweat going. But the classic methods — fire, hot coals and stones, dousings of water — persist.

In Boulder, PORTAL Thermaculture started as a pop-up Finnish-style sauna expected to close in April; it’s still going strong in June, however, and now looking at permanent spots in Boulder and Denver.

“I, personally, have always had saunas in my life, being from the northern Midwest,” said PORTAL founder and Minnesotan Will Drescher. “I think the old-school banya” — the Russian version of a sauna — “existed in a different time and place, so what we’re trying to do is offer an update.”

PORTAL features two stove-heated saunas and three cold-plunge tubs. Guests get heated in a sauna at around 200 degrees Fahrenheit, then lower themselves into a cold tub, then repeat.

“I think it’s a powerful tool for healing,” Drescher said.

Denver Mobile Sauna, owned and towed by another Minnesotan, Micah Mitlyng, offers a similar experience, on the go. Mitlyng said he discovered the benefits of sauna after the death of his father and birth of his child.

“I felt that my body was able to process that grief better, and the things that I was holding in,” said Mitlyng, who relocated to Colorado in 2022 and found the sauna scene lacking.

Mobile saunas were already tooling around the Minneapolis metro, so Mitlyng built two to share with his new home state. He rents the trailer-mounted saunas to running events, yoga meetups, meditation gatherings and day-after wedding festivities. (The cold-plunge tub is an optional add-on.)

“People need more connection,” Mitlyng said. “They need to take a break from looking at their phones. … The community aspect is what really excites me.”

TikTok videos with millions of views tout an impressive array of supposed health benefits: Reduced risks of cardiovascular disease; weight loss; age-fighting properties; and the ever-popular “detox” appear over and over again.

One frequently cited 2018 study, published by a group of researchers from Finland (one of sauna’s original hotspots), did show fewer fatal cardiovascular events among habitual sauna users. But those researchers acknowledged that one study among one population isn’t a definitive conclusion.

Internal medicine physician and University of Colorado associate professor Dr. Adam Gilden is also a tad skeptical of the more extreme health claims among sauna superfans.

“It’s a nice thing to do socially and is relaxing and maybe lowers blood pressure for a day or two,” Gilden said. “it’s not a real intervention we do, though. … I can’t think of a purely medical reason why I’d recommend someone go to a spa.”

For Drescher and Mitlyng, possible health advantages are just one part of a sauna’s appeal. Both see the practice as a social outlet, a “third space” that’s often missing in the Internet age.