Jon, Garfield, and Odie are forced to stay in an old and abandoned hotel after the car breaks down in front of it. Jon plays a prank on Garfield and Odie by telling them that a "sludge monster" lurks in the hotel.

Garfield combats a hot July day by "thinking cool," leading him to set up Christmas decorations. Jon, Odie, and the entire town soon follow suit, prompting a summer holiday.