King of the Hill - Season 12 Episode 4 -

Arlen is hit by a heat wave and Hank and the gang take the kids to the water park. Unfortunately, when they have to tangle with a group of surfer bullies, Boomhauer, who is usually cool, winds up embarrassing himself. Meanwhile, Bill becomes known as the famous "Heat-Waver" when he begins to stand on the side of the highway and wave to motorists.