Red Dwarf: Season 3, Episode 4

3 - 4: Bodyswap

A skutter goes berserk and rewires all the ship's circuitry. So when Lister orders a chocolate bar from one of the snack dispensers, he accidentally triggers off the ship's self-destruct sequence. There is only one way to diffuse the bomb, but it involves Lister lending his body to a female officer. This gets Rimmer thinking...