What was a sweat lodge and What was a sweat lodge used for?

A sweat lodge was a small dome-shaped structure made out of bent poles covered with hides.

Men gathered in these structures as part of a religious ceremony. In the center of the sweat lodge they placed a pile of stones that had been heated in a fire. Pouring cold water over the stones, the participants filled the lodge with steam, causing them to perspire profusely.

The sweat lodge ritual was thought to cleanse both the body and the spirit.