On a trip in May, I had already visited Helsinki's elite Finnish Sauna Society, a bastion of purist practices. I had plunged into the icy waters of a river near the Arctic Circle. I had even been to corporate Helsinki's equivalent of lunch at the Palm: the power sauna atop the Palace Hotel.
But now I stood naked in a dilapidated and soot-covered wooden shack in Espoo, a Helsinki suburb.
To the left was a wood-burning oven: a pile of rocks five feet high and six feet in diameter at the base. In front was a rickety wooden ladder up to the loft. Up in the rafters, about half a dozen men sweated as they sat in almost pitch-black darkness.
As I climbed up, the temperature rose sharply and the heat bore into my skin. Someone tossed water over the rocks, creating an intense blast of steam that Finns lovingly call the loyly (pronounced somewhat like LOH-loo).
''Once you have been in a smoke sauna,'' said Matti Kivinen, a burly and bearded veteran of saunas who accompanied me, ''you will never want to go back to an electric one.''
I had my doubts. But an hour and a half later, I was feeling good enough to believe anything. I had endured three sessions in the rafters, and doused myself in icy water after each.
Between sessions, I cooled off outside, where men cooked sausages on an open grill. Steam rose off our skin in the chilly evening breeze but we couldn't feel the cold.
I felt electric, euphoric and yet utterly relaxed.
''People in other countries often talk about all kinds of health benefits from the sauna,'' said Dr. Lasse Viinikka, a surgeon and board member of the Finnish Sauna Society who had come by that particular evening.
''The truth is, there have been all kinds of studies and there aren't really any health effects. It just makes you feel good.''
That was perhaps the key lesson of Finnish sauna culture: it just makes you feel good. At least to Finns, the sauna is a pleasure that is hedonistic yet spiritual. It is also a revered refuge from stress that can be a family activity, a social event and sometimes even a religious experience.
This year, Helsinki is highlighting 12 of the area's most distinctive saunas, each a ''sauna of the month.'' They range from cavernous public spas to tiny private hideaways, and they were chosen to display saunas as a Finnish social institution.
True, it is a publicity gimmick. But the program offers foreign visitors a unique chance to experience a remarkable diversity of saunas as well as the many ways that Finns take them.
One purpose of my sauna tour was to have a window on Finnish culture. The other was to see how the people who largely invented sauna culture actually do it themselves.
''Sauna'' is one of the very few Finnish words that has made its way into English and most other Western languages. But to hear Finns talk, American saunas and sauna habits are as tepid and hurried as instant decaffeinated coffee.
