they used to build a small log house without windows, and would light a fire in the center of the room. keep it going for a while, then add stones, let it smoke and burn all day. then let it burn out, and sit in there smacking themselves with oak branches. quite a party.

Women would give birth in there, because they believed the smoke and steam drove out the evil spirits. which is another way of saying the heat, smoke, and steam completely sterilized the room.