Noun
sweat hole (plural sweat holes)
(rare, archaic or nonstandard) An opening in the skin through which sweat is excreted; pore.
A large hole in the ground, heated with a fire, into which a sick person is brought wrapped in blankets (once the fire is removed), with a jug of water for making steam, the whole covered by an awning to hold the steam in; an underground sweat lodge.
An uncomfortably hot, enclosed, space.
Source: en.wiktionary.org