Farscape - Season 1 Episode 2 -

Moya is invaded by some creatures. They increase the heat on Moya, and they're creating replicas of the crew. Peacekeeper cannot stand heat, Aeryn starts to suffer Heat Delirium. The crew must figure who is real and who is a replica, and shut down the heat. They must also contend with a Peacekeeper squad that's searching for Crichton.