A sauna is a small room or house designed as a place to experience dry or wet heat sessions, or an establishment with one or more of these and auxiliary facilities. These facilities derive from the Finnish sauna. The word sauna is an ancient Finnish word refering to the traditional Finnish bath as well as to the bathhouse itself.
Historical evidence and records indicate that the Finns built the first wooden saunas in the 5th or 8th century. Early saunas were dug into a hill or embankment. As tools and techniques advanced, they were later built above ground using wooden logs. Rocks were heated in a stone fireplace with a wood fire. The smoke from the fire filled the room as the air warmed. Once the temperature reached desired levels, the smoke was allowed to clear and the bathers entered. The wood smoke aroma still lingered and was part of the cleansing ritual. This type of traditional smoke sauna was called a savusauna, which means "smoke sauna" in Finnish. Many people find the smell of smoke and wood to be relaxing.
Eventually the sauna evolved to use a metal woodstove, or kiuas, with a chimney. Air temperatures averaged around 160-180 degrees Fahrenheit (70-80 °C) but sometimes exceeded 200 °F (90 °C) in a traditional Finnish sauna. Steam vapor was created by splashing water on the heated rocks. The steam and high heat caused bathers to perspire, thus flushing away impurities and toxins from the body. The Finns also used a vihta or vasta, which is a bundle of birch twigs, to gently slap the skin and create further stimulation of the pores and cells.
The Finns also used the sauna as a place to cleanse the mind, rejuvenate and refresh the spirit, and prepare the dead for burial. The sauna was (and still is) an important part of daily life, and families bathed together in the home sauna. Indeed Sauna was originally a place of mystical nature where gender/sex differences did not exist. Because the sauna was often the cleanest structure and had water readily available, Finnish women also gave birth in the sauna.
Eventually the sauna evolved to use a metal woodstove, or kiuas, with a chimney. Air temperatures averaged around 160-180 °F (70-80 °C) but sometimes exceeded 200 °F (90 °C) in a traditional Finnish sauna. ll saunas have a basket of rocks heated by the stove on which to throw water to increase the humidity. Called the "löyly" in Finnish, it increases the feeling of heat and causes bathers to perspire, thus flushing away impurities and toxins from the body. The Finns also used a vihta or vasta, which is a bundle of birch twigs, to gently slap the skin and create further stimulation of the pores and cells.
When the Finns migrated to other areas of the globe, such as Minnesota, Northern Wisconsin, the Upper Pennisula of Michigan and Western Ontario, they brought their sauna designs and traditions with them, introducing other cultures to the enjoyment and health benefits of sauna. This led to further evolution of the sauna, including the electric sauna stove, which was invented and implemented in the 1950s and far infrared saunas, which have become popular in the last several decades. Infrared saunas use a special heater that generates infrared radiation rays similar to that produced by the sun. Unlike the sun's ultraviolet radiation, infrared is said to be beneficial to overall health. Infrared radiation has been shown to kill the bacteria responsible for acne. In an infrared sauna, the electric heaters warm the air and also penetrate the skin to encourage perspiration, producing many of the same health benefits of traditional steam saunas.