The sweat loge (also called sweat house, medicine lodge, or medicine house) is a ceremonial sauna and an important ritual used by North American First Nations or Native American peoples. There are several styles of sweat lodges that include a domed or oblong hut similar to a wickiup, a teepee, or even a simple hole dug into the ground and covered with planks or tree trunks. Stones are typically heated in an exterior fire and then placed in a central pit in the ground. Often the stones are granite and they glow red in the dark lodge.