Sweat lodge

The sweat lodge (also called purification ceremony or simply sweat) is a hut, typically dome-shaped and made with natural materials. It used by Native Americans for ceremonial steambaths and prayer. Sweat lodges were largely a reaction to the influences of European culture with its negative effects on Native Americans. 
There are several styles of structures used in different cultures. These include a domed or oblong hut similar to a wickiup, a permanent structure made of wood and earth, or even a simple hole dug into the ground and covered with wood. Stones are typically heated and then water poured over them to create steam. In ceremonial usage, these ritual actions are accompanied by traditional prayers and songs.
Native Americans in many regions use the sweat lodge. For example, Chumash peoples of the central coast of California build sweat lodges in coastal areas in association with habitation sites. The ancient Mesoamerican tribes of Mexico, such as the Aztec and Olmec, practiced a sweat bath ceremony known as temazcal as a religious rite of penance and purification.