An enclosure in which a person is exposed to moderate to very high temperatures and often high humidity, produced by water poured on heated stones. A stay in the sauna may be followed by a cool bath or shower. Sauna water is not sterile and may contain harmful microorganisms, including yeasts and molds. Even though the sauna has no proven benefits in preventing illnesses or promoting fitness, the regimen does help to promote relaxation, relieve aches and pains, and loosen stiff joints.