I quickly learned that few hotels can manage the insurance needed for a fire-heated sauna, but Finns with country houses would be ashamed to use an electric stove. The quintessential Finnish sauna is heated to more than 200 degrees by a wood-burning stove, with granite rocks set on top to hold the warmth. You recline on an aspen bench, looking out a window that frames birch trees and water, and sweating from the heat radiating off the wooden walls. You create hisses of steam by ladling water onto the stones. You lightly beat yourself and your friends with a vihta, a whisk of birch branches, to help the circulation. After 20 minutes, when you feel as if you could burst with aromatic heat, you plunge into an impossibly cold lake, the frigid sea, or a snowbank. With all the heat inside you, you're immunized against the chill for a few seconds. Then you go back inside and start all over again.
Nothing could be more primal, more sensual, than the physiological effects of those drastic temperature shifts, except, perhaps, the holiest of saunas, the smoke sauna. People speak of the smoke sauna, or savusauna, in hushed tones. Within a chimneyless room, black smoke fills the air, then gradually escapes through small vents in the walls. "Left in so long, that smoke-heat slowly, slowly becomes soft, like porridge," says Outi Heiskanen, a famous Finnish artist. "When you come out, you're all black, but you are so clean."
In my travels, I experienced only two smoke saunas. One of them, at Hotel-Spa-Hostel Rauhalahti outside the town of Kuopio, claims to be the biggest in the world. When I entered its vast, dark interior, wrapped in a white sheet, the heat seemed silky, like a caress. Surprisingly, it didn't make me black or sooty.
The other smoke sauna was just outside Helsinki, at the Finnish Sauna Society. I went there one Thursday, a "ladies' day," and watched as women of all ages, shapes, and sizes put their briefcases and cell phones in lockers and disappeared into one of the small chambers worn smooth with age and blackened smoke. I saw contemporary women transformed into a timeless tribe, comfortable in their nudity and their communality. After the sauna, I reclined with the others on the shore rocks, all of us like so many sirens wrapped in towels. Though I'll never see it, I'm sure the scene on the days I'm forbidden to enter the Sauna Society look just like one of D. H. Lawrence's Nordic dreams—men stalking about the way nature made them.
MY FAVORITE MODERN SAUNAS are at two of Helsinki's tried-and-true hotels. The Strand Inter-Continental, on a city embankment, has a top-floor steam room with red-railed terraces where you can drink your mid-sauna beer in the open air, overlooking a glorious landscape of boats and wooded islands. The Scandic Hotel Continental on Toolo Bay, near the Opera House, has a top-floor sauna as well, with one massive wall of glass. As you sweat, you can look out from the inland bay to the heart of the city and its faux-medieval turrets. Instead of the usual dark chamber, it's a window on the world.
And then there's the sauna in the new Hotel Kämp, Helsinki's first luxury hotel. Behind the overly ornate façade of an 1887 hotel of the same name, once the famous drinking spot of the composer Jean Sibelius, the Kämp is now done up in the all-purpose marble-and-mahogany, ritzy men's-club mode. Its top-floor sauna is so lavish, it's almost a perversion: Roman and Turkish motifs overwhelm the room, and gilt lions spit ice cubes from the tiled walls.
To recover from the bourgeois excesses at Hotel Kämp, I walked over the footbridge to the island of Seurasaari, Helsinki's open-air museum of Finland's rural past. Amid sawmills, mansions, and churches rescued from different parts of the country stands the Niemelä Tenant Farm, a collection of old tepees, lean-tos, and cottages made of what looks like piles of unpainted twigs. The oldest structure is the smoke sauna (built in 1844), with a rickety ladder leading up to a crude bathing platform. I could almost see those ancient Finns, wrapped in furs, snowshoeing home through the forest to that sauna.
Now a confirmed sauna addict, I went back to Finland this winter to try a sauna in the bone-chilling cold. This time I headed to the old capital, Turku, a couple of hours by train from Helsinki on the west coast. Ulrika and I had booked the sauna at Turku's castle-like Park Hotel before we knew there was a blizzard coming, but we kept our reservation anyway. That night was the high point of my sauna quest. We trudged through heavy snow to the steam house, then sat sweating, watching through the window as crystalline-blue snowflakes hurtled from the sky. The stove threw an orange glow on our bare skin. And we were so warm.