Krabs à la Mode SpongeBob SquarePants : Season 5 Episode 8

Plankton alters the Krusty Krab's thermostat as part of another Krabby Patty stealing scheme. It backfires on him when Mr. Krabs turns the Krusty Krab into a skating rink. Plankton goes in and attempts to steal a patty himself but gets pummeled. He freezes the customers, but Mr. Krabs stops him and sets the thermostat. The Krusty Krab is turned into a popular public pool the following summer.