sweatbox

/S W EH1 T B AA0 K S/
noun
  1. 1

    Any box or boxlike structure used to induce sweating, such as of hides or tobacco

  2. 2

    A jail cell.

  3. 3

    A small overheated cell or room used for solitary confinement or torture.

  4. 4

    A small nightclub packed to capacity where people get hot and sweaty.

Source: https://en.wiktionary.org/wiki/sweatbox