A cryo-chamber is a plastasteel chamber that allows all of a starship's non-essential personnel to be cryonically frozen for long periods of time. An example of its use would be during prolonged Slipspace jumps. They are basically large metal pods with form-fitting gel beds where the personnel are frozen until they are needed. An example of this is John-117, who was stored in a cryo-chamber aboard the ship UNSC Pillar of Autumn and later unhatched from the cryosleep chamber by Tech Chief Thom Shephard along with Tech Officer Sam Marcus.