One recent evening, I went to a foreign embassy and got naked with about 20 strangers—mostly Hill staffers, journalists, and a few Finnish people. This was a formal, and very exclusive, event held by the Diplomatic Sauna Society, a Scandinavian-flavored networking club established by a spokesman of the Finnish embassy in D.C. to help the country’s diplomats forge connections with Washington heavyweights. As the founder, Kari Mokko, explained to a Washington Post reporter in 2010, “We needed something to catch attention.”

Saunas feature in all Finnish embassies, according to Sanna Kangasharju, a diplomat who now runs the society. But she told me via email that many are mainly for the use of embassy staff and can’t accommodate events. Still, she said, “Inviting guests to the sauna is an old Finnish way of hospitality, and whenever possible, we like to offer this hospitality also when living abroad.” The D.C. embassy sauna is unique in taking this practice to the next level—for instance, it’s the only one that issues “sauna diplomas” to guests for basically spending an evening in a steam room with some Finns. And it also, through the Diplomatic Sauna Society, holds monthly gatherings to promote the culture of the sauna—and, by extension, the culture of Finland.

Little says Finland quite like a sauna. The word itself is Finnish, and in the country of some 5 million, there are roughly 2 million saunas, an average of about one per household. Taking a sauna is a centuries-old tradition that started in the rural parts of the country as a way for farm workers to get a reprieve from the cold weather, and the practice gradually worked its way into urban areas. According to Finland’s official Sauna Society (a Helsinki-based group, not to be confused with the Diplomatic Sauna Society, whose purpose is to preserve and promote sauna culture locally): “At its most primitive, the sauna was probably a pit dug into a slope, with a heap of heated stones in one corner.” As recently as the turn of the 20th century, women in rural areas would give birth in a sauna; the room would also be used to prepare dead bodies for burial.

Saunas get hot by means of a stove that heats a basket of rocks. Ladling water onto the rocks, with an instrument the Finns call a löylykauha, creates a wave of steam, or löyly. It’s typical for the temperature of a Finnish sauna to reach as high as 190 degrees Fahrenheit. And Finns evidently love it: It’s been reported that 99 percent of them use a sauna at least once a week. They also tout the benefits of a good steaming—one recent study from a Finnish university found that men who used saunas seven or more times per week were less likely to die of heart disease than men who used a sauna once a week. This is not to say there’s no such thing as overheating; at the 2010 World Sauna Championships—a competition hosted in Finland over who can sit the longest in extreme heat—a Russian contestant died after spending six minutes in a sauna heated to 230 degrees Fahrenheit.

The Diplomatic Sauna Society dates back to 2003, when the Finnish embassy invited Kevin Maney of USA Today to sit in the sauna with some other journalists and write about the experience. The society matured into its current form by 2008, when Mokko took charge of organizing the monthly meetings. His zeal is credited with elevating the event to the status of a tradition. He was widely acknowledged by my fellow sauna-goers to be “a great guy” with a great sauna “presence,” which sometimes included dousing the sauna rocks with beer. Mokko has since left D.C. to become the director of communications for the Finnish prime minister, but he left plenty of disciples behind.

Sauna diplomacy is not just a quirk of D.C.’s Finnish embassy. Urho Kekkonen, a Cold War-era president of Finland, was reputed to have used the sauna to soften up the Soviets. Legend has it that when Soviet premier Nikita Khrushchev came to Finland for Kekkonen’s 60th birthday, the two stayed in the sauna until 5 o’clock in the morning. As Finland’s then-Secretary of State Pertti Torstila recounted the tale at the 15th International Sauna Congress in 2010: “At the end of the visit a communiqué was issued in which the Soviet government expressed its preparedness to support Finland’s desire to integrate and cooperate with the West.”

Torstila noted in the same speech that Martti Ahtisaari, a former Finnish president, also employed the tactic as Finland’s ambassador to Tanzania in the 1970s: “The Tanzanian Foreign Minister John Malecela, who later on became Tanzania’s prime minister, was a regular visitor in the Ambassador’s sauna.” Torstila explained: “Decisions and negotiations take less time in the high heat. Sauna cools down overexcitement and melts away political differences.”

Serious negotiations inside a sauna are rare, however. In the D.C. embassy, the sauna serves as more of a medium for cultural exchange. Kangasharju herself curates guest lists of up to 25 people a month to visit it, and she tries to get a coed mix of Washington professionals, mainly journalists and politicians, particularly those associated with the Friends of Finland Congressional caucus. Almost everyone there when I went was between 35 and 55 years old; at 26, I was both the youngest and least-established person at the event. (I had heard about the society from a stranger in a coffee shop and phoned the embassy to ask whether, as an Atlantic employee, I could attend and write an article about it. The person in charge of cultural relations turned me down, so I tried my luck with the person in charge of press relations, who turned out to be Kangasharju. She said the guest list was full, so the sauna would be “cramped,” but she would “squeeze me in.”)

As a networking soiree, the event was simultaneously sweatier and less slimy than others I’ve attended. Guests were first treated to “flowers”—specialty drinks composed of Finlandia cranberry vodka mixed with pink lemonade. That was followed by an authentic Finnish dinner of gravlax with mustard sauce, smoked salmon, potato salad, beef meatballs, and glazed carrots, with a dessert of cheesecake topped with fresh berries.

After dinner, my male dining companions and I headed for the main event. (The women took their sauna separately.) The sauna itself was so dark and foggy that I couldn’t see more than three feet in front of me. The room was a double decker, and all but two of the men sat on the second deck. After a toast with Bud Lights (Kippis, as the Finnish say), we went around the room introducing ourselves and explaining how we ended up at the Finnish embassy that night. A few of the men were founding members of the society, on Mokko’s original guest list. Others were either Finnish nationals, journalists who had interviewed Finnish diplomats and were subsequently put on the guest list, or Hill staffers whose connections to Finland were never clarified.

All seemed to be there to unwind, and the conversation did in fact revolve around Finnish culture. I learned that the American ambassador to Finland, Bruce Oreck, is the unique diplomat who has tattoos and body piercings. I also got confirmation that Finnish people generally only greet each other once a day; an American expat in Finland recently recounted in The Atlantic his experience being corrected for greeting a colleague he had already said “hi” to earlier.

Clearly, then, the event achieved its goal of enhancing knowledge about Finnish culture. Kangasharju explained to me her belief that sauna diplomacy works because of its relaxed nature, and in fact it was easy to see how the locker-room-like setting could facilitate trust in a way that can’t be achieved in an austere conference room. Maybe other diplomats could learn something from this. In the meantime, I’ve earned my sauna diploma.