Variations of saunas have been a part of ancient civilizations since before the Dark Ages.
Finland is widely recognized as the world leader in sauna use and scientific research. One of the first historical records of a sauna is in 1112 in Finland. The sauna was dug into an embankment in the earth. Later they evolved into buildings of wood and stone. These early saunas were heated by a log fire in an enclosed room. It took nearly half a day for the room to come to temperature. Then the smoke was allowed to escape via an air vent, and sauna bathers would enter. Sauna culture was so entrenched in Finnish society that migrating Finns took their love of heat therapy along with them when they colonized in Delaware, United States in 1638.
Historical Finnish saunas were used for far more than just sweating. With a reverence like unto a religious site, saunas were healing sanctuaries. Women gave birth in them. Doctor treated patients. Ailments were cured. The elderly even passed away in the comfort and relaxation of the dark, warm room. Beyond that, they prepared their food and cured meats within those heated walls.
Although saunas have rural beginnings, they were developed for cities as well. Communal saunas rose up among dwellings. They were designed with dressing rooms and sometimes divided by gender. Those who were able opted for private saunas in their own homes. Today, Finland boasts nearly three million saunas–that is nearly one to every two people in their entire country.
Finnish culture is not the only one, however, to recognize the power of heat therapy. The first mention of an early Korean sauna was in the 15th century. It was a domed structure made of stone and praised for its healing capabilities.
Native Americans built sweat lodges of similar craftsmanship to early Finnish saunas. They were usually dome shaped, made of wood, stones, and mud, and dug partially into the earth. Stones were heated outside the lodge, brought inside, and placed in a small pit or on an altar. Sweat lodges were highly sacred and used to mark special occasions or in times of prayer.
During World War II, Finnish soldiers built saunas in tents and bunkers. German soldiers enjoyed sauna culture so much it resulting in them bringing it back to their native country. This eventually spread to neighboring countries such as Switzerland, the Netherlands, and Belgium.
Technology continues to aid the ease of access to saunas. The electric sauna stove was developed in the 1950s and is likely the most common heating element for saunas today; although they can still be heated by fire or gas heat. Stones are placed on top of the heater to radiate and maintain the temperature in the room.
The ancient practice of heat therapy is one that continues to prove its medicinal benefits for the human body.