The Portable Cryogenic Statsis Apparatus is much like a body bag, except with a small box attached to it, tending to the things inside. When the cryo unit is activated, the polymer bag goes rigid, forming a vessel into which a person can be placed and put into safe and functional cryogenic suspension for a short period of time due to the unit's power supply. It uses energy to keep the bag rigid to protect the person inside, and to keep them frozen after all. And of further note, Marines will happen to store fresh food in them. And drinks.