A sauna session can be a social affair in which the participants disrobe and sit or recline in temperatures of over 80 °C (176 °F). This induces relaxation and promotes sweating.

Saunas can be divided into two basic styles: Conventional saunas that warm the air or infrared saunas that warm objects. Infrared saunas may use various materials in their heating area such as charcoal, active carbon fibers, and other materials.

Etymology

The word sauna is an ancient Finnish word referring to the traditional Finnish bath as well as to the bathhouse itself. The proto-Finnic reconstruction is *savńa. There are etymological equivalents in the Baltic-Finnic languages such as the Ingrian and Votic word sauna, Estonian saun and Livonian sōna. The word suovdnji in Sámi means a pit dug out of the snow, such as a hole for a willow grouse. In Baltic-Finnish, sauna does not necessarily mean a building or space built for bathing. It can also mean a small cabin or cottage like a cabin for a fisherman.

First saunas

The oldest known saunas were pits dug in a slope in the ground and primarily used as dwellings in winter. The sauna featured a fireplace where stones were heated to a high temperature. Water was thrown over the hot stones to produce steam and to give a sensation of increased heat. This would raise the apparent temperature so high that people could take off their clothes. The first Finnish saunas are what nowadays are called savusaunas, or smoke saunas. These differed from present day saunas in that they were heated by heating a pile of rocks called kiuas by burning large amounts of wood about 6 to 8 hours, and then letting the smoke out before enjoying the löyly, or sauna heat. Rightly heated "savusauna" gives heat up to 12 hours. These are still used in present-day Finland by some enthusiasts, but usually just on special occasions such as Christmas, New Years, Easter, and juhannus (Midsummer).

Evolution

As a result of the industrial revolution, the sauna evolved to use a metal woodstove, or kiuas 2, with a chimney. Air temperatures averaged around 70–80 degrees Celsius (160–180 degrees Fahrenheit) but sometimes exceeded 90 °C (200 °F) in a traditional Finnish sauna. Steam vapor, also called löyly 3, was created by splashing water on the heated rocks.

The steam and high heat caused bathers to perspire. The Finns also used a vihta 4 (Western dialect, or vasta 5 in Eastern dialect), which is a bundle of birch twigs with fresh leaves, 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, the sauna was originally meant to be 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.