The Deep Fryer Cage - from The QuakeLab is a Single Player level. There is no in-game name for this level, the name comes from documentation included with the file.
Walkthrough
Proceed forward onto the pool of Lava to pick up the Silver Key. An Elevator will raise, placing you in a cage, before lowering after a moment. Stand in the middle of the Elevator cage to not get injured by the Lava.
Gallery
The Deep Fryer Cage - from The QuakeLab