Finns are concerned that the sauna, the health-giving steambath they have been taking for generations, has become associated abroad with sex.
"Of course, we have no copyright on the word sauna, but it is a cause of annoyance to the Finn when he sees the word being misused in other countries," Pirkko Valtakari, executive secretary of the Finnish Sauna Society, said recently.
The society and its sister organization, the International Sauna Society, are campaigning to stop foreigners from using the word sauna to describe what they say are often really massage parlors and houses of prostitution.
The societies are asking Finnish embassies and missions abroad to help uphold the wholesome image of the sauna.
According to a Finnish saying, one should behave in the sauna as if in church.
Valtakari said that in Finland only members of the same family would take a mixed sauna.
"Here we are very strict about segregating men and women in the sauna," the society's honorary president, Harald Teir, told a visitor to its sauna headquarters on Lauttasaari Island in Helsinki.
Guardians of the true faith say the sauna should be heated by a wood fire, as is the society's sauna among the birch and pine woods on Lauttasaari.
"My father was born in a sauna. Many of his generation were. The sauna was considered the most hygienic place in a house," said Teir, a retired physician and mentor to the society's 1,900 members.
As he escorts visitors into the dark, slightly acrid-smelling sauna, Teir recalls the day in 1983 when George Bush, then-vice president, came as a guest.
"I realize the need for security," Teir said, "but when he came here, I had to draw the line at armed guards coming into the sauna.
"We still exchange letters. I have invited him to come back to celebrate my 100th birthday in the sauna," said Teir, adding that this would be in the year 2014.
The smoky atmosphere and soot on the ceiling and upper benches at Lauttasaari contrast with the gleaming white pine appearance of most modern saunas.
"This is the real Finnish sauna. I have heard the Swedes read newspapers in their saunas, but not here," said Teir, flicking water onto the hot stones with a birch swish to produce a stinging wave of steam.
In the half-gloom, a visitor once accidentally spilled a whole tub of water over the stones. "It was like an atomic explosion," Teir said. "He was surprised when we Finns hit the floor as if we were under attack."
In Finnish culture, traditional uses of the sauna included curing ham, threshing grain and drying linen. The sauna is also known to inhabitants of the Siberian tundra and North American Indians.
Businessmen and politicians often take their visitors to the sauna, believing that hostility vanishes in the steam and that rank and protocol are shed along with one's clothes.
Prime Minister Harri Holkeri's male cabinet members often take a joint sauna at their weekly meeting in his official residence, a government spokesman said.
Bathers emerge from the Lauttasaari smoke sauna streaked with soot from the benches, looking like blackened, barbecued lobsters. The hardier types walk along a heated path to the end of the private jetty and plunge into the Gulf of Finland.
The society advises against drinking alcohol while taking a sauna, but not all Finns accept this stricture.
"I remember when a man's affluence was measured by the amount of vodka he could buy for the Friday night sauna," said one businessman.
The International Sauna Society groups Finland, Austria, Japan, West Germany, the Netherlands, Norway and Switzerland. It aims to publicize the sauna culture, encourage its use and promote scientific research.
Next year the society holds its quadrennial congress in Japan.
"The Japanese have their own ancient bathing culture," Valtakari said, "but we are teaching them how to take a real sauna."