Is Cold-Shocking Your Body After a Sauna a Good Idea?

sauna cold plunge
This outdoor sauna in Vuokatti, Finland, comes complete with an icy plunging pool for visitors brave enough to use it. Wikimedia

If the idea of topping off your next trip to the sauna with a plunge in to a cold bath sounds torturous, you may soon be alone. This hot to cold spa treatment is growing in popularity among sauna lovers and celebrities across North America, although its chilly origins are some 3,000 miles (4,828 kilometers) away.

The Finnish are often credited with starting the hot-to-cold practice. That's not a huge surprise, given that the Nordic country has 2 million saunas with a population of 5.3 million people; that's about one sauna for every two Finns, according to the Finland tourism board.

Finland and the Hot Sauna

Saunas are part of a toasty tradition that is as entwined with Finland as the snow that falls there. Saunas originated as sterile ways to "wash up" before running hot water existed. The word sauna is actually a Finnish word that translates into English as "bath."

The first Finnish saunas were dug into ridges in the ground, and later were built above ground from wooden logs. Rocks were heated until in a stone stove using a wood fire. But these first sauna rooms didn't have chimneys and bathers would have to wait until the rooms cleared of smoke. Finally saunas evolved to what we know today: They're traditionally heated by metal stoves and can reach temperatures as hot as 200 degrees Fahrenheit (93 degrees Celsius).

Winters in Finland can last up to seven months in the northernmost regions; hence the need for extremely hot saunas. But what about that cold plunge? Well it provides an equally extreme way to cool off. As the Finland tourism board describes it:

"When you come out of the sauna, jump into a lake, or roll in the snow. If you do roll in the snow, make sure it is fresh and powdery: old, icy snow can have an effect on your skin like sandpaper."

Rolling in the snow sans clothes — oh right, did we mention many Finns do this naked? — may sound like the worst spa experience ever. But according to Dr. Mark Timmerman, a family physician and sports medicine specialist in Wisconsin, the Finns are on to something.

snow grotto
The snow grotto on Viking Cruises has become very popular among guests, especially after a long soak in the hot tub or sauna.

Health Benefits of Hot Sauna, Cold Plunge

As your skin temperature increases, sauna-goers experience a "fight or flight" response, resulting in a heightened sense of alertness, reduced pain perception and an elevated mood, Timmerman said in an article for The North American Sauna Society. When you follow up a sauna with a plunge in cold water or snow, he explained, your adrenaline raises, as well.

Beyond adrenaline, Timmerman said the hot sauna, cold plunge practice can improve pain and inflammation from rheumatoid arthritis — a disease that's often worsened by sauna visits that aren't followed by some cold.

Health benefits, including boosting circulation and releasing toxins, are reasons upscale ocean and river cruise company Viking Cruises, now has hot and cold spa experiences aboard its ocean ships. The second reason? The family-owned company has strong ties to its Norwegian heritage and traditions — including the Nordic hot sauna, cold plunge experience.

While the variety of hot and cold spa options are enticing, few excite guests as much as the elaborate snow grotto. This surreal, snowy room immerses cruise-goers in the real Nordic bathing tradition. The stone-walled grotto has actual snow that's produced similarly to the artificial powder at ski resorts.

Now, I'm not one for rolling through snow in the nude, but even I couldn't resist trying the snow grotto (in a swimsuit) while cruising up to Norway. It's about the size of a walk-in closet, with a snow-covered bench for those brave enough to sit. (I stood.) The grotto's purple lighting and snowy, forest décor make it feel like a movie set from "Frozen" — one of the many reasons I kept going back. I alternated between shivering in the grotto then sweating in the hot tub and sauna for at least two hours, two days in a row. Did I feel toxin-free by the end of it? Not really. But I did feel relaxed, pampered, and much more ready for the Norwegian snow ahead.

Of course, the snow in Viking's grotto isn't actually real snow. The system combines compressed air and water to form ice crystals, then blows the snow into the chilly grotto, which is temperature controlled to maintain the snow's consistency. Spa staff de-frosts and generates new snow every few days to keep the grotto looking its best.

Health Risks of Hot Sauna, Cold Plunge

While the toasty sauna followed by cold plunge — or hut tub followed by snow grotto — is rejuvenating and safe for most, it's not for everyone (a fact Viking makes clear to guests). In fact, those with heart conditions should stick to milder spa experiences.

Cold receptors in the face and scalp respond to the quick drop in temperature. This stimulates the "diving reflex," a complex cardio respiratory reaction. It can cause shortness of breath, decreased cardiac output and rapid decrease in pulse.