The Hotseat is one of the Industrial Zone's most iconic gunge devices as well as one of the simplest games. A player is seated inside a booth cut into the wall, which has a waist-high metal panel as its front door that can be lowered then raised to allow walking inside. The booth is lit from above in green, with a dazzling array of computer panels, pipes and lights lining its inner walls.

The player is asked three questions and must answer all three of them correctly to escape the gunge tank clean - their score isn't announced until all three questions have been asked and answered. Sometimes, the option is given to let the player's teammates answer on their behalf.

If even a single wrong answer is given, the player is first sprayed with a set of jets of green gel from the left and right front edges of the tank, playing up and down them to coat their front. After a few seconds, the main tank above them is opened and they're showered by a flood of smooth opaque slime that's usually yellow or orange. After both tanks have run out, a third tank pours a heavy black lumpy gunge on to them from above, leaving them completely coated in a sickly mixture of slime.