The Thermanator is a gadget in Going Commando created by a Gadgetron inventor stranded on Barlow. It allows the user to thaw ice or freeze any pool of water (though it cannot be used to freeze oceans).
Ratchet first finds the inventor on Barlow, left stranded after freezing himself in an ice cube. When he is released, Ratchet informs him that MegaCorp has driven Gadgetron out of business in the Bogon Galaxy, leading the inventor to instead sell the Thermanator to Ratchet.
The Thermanator can be used in many instances to freeze water and allow Ratchet to cross a path, or otherwise to thaw ice and allow Ratchet to swim through it. Sometimes, Ratchet must carefully freeze water when the pool of water or the objects within it have reached a certain point. In some cases, the Thermanator can be used to unlock secrets.