It is a light yellow box with a black scroll button that adjusts the temperature.
Role in series
"Krabs à la Mode"
It is the main focus of this episode. On a cold day at the Krusty Krab, Squidward
tries to increase the temperature on the thermostat, but Mr. Krabs yells at him and tells him that no one can touch the thermostat except for himself.
Later, Plankton uses the thermostat to freeze the Krusty Krab.
At the end of the episode, Plankton uses the thermostat to freeze and unfreeze Mr. Krabs, SpongeBob, and all of the other Krusty Krab patrons until he accidentally falls off the thermostat and is trapped by Mr. Krabs. Mr. Krabs then uses the thermostat to melt all of the ice and transforms the Krusty Krab into a swimming pool.
"Planet of the Jellyfish"
It is seen in the Krusty Krab freezer. SpongeBob and Sandy increase the temperature so that the mayonnaise unfreezes. They then use the mayonnaise to destroy the Jelliens.
"Eek, an Urchin!"
It is used to freeze the Krusty Krab kitchen, so that the sea urchins can be trapped inside a garbage can.
In "Krabs à la Mode," the thermostat is set to 62 degrees.
In "Eek, an Urchin!," the thermostat is set to 70 degrees.