The kids build an endless ice luge to beat the heat while Doof brings oil to a waterpark.
Plot[]
On a hot day in Danville, Phineas and the gang attempt to keep cool, when Baljeet suggests they "luge the heat" (meaning to have said, "lose the heat"), which gives Phineas the idea for the day. Inside the house, Candace is boiling hot since the air conditioner is broken, when a breeze from the boys' ice luge wheel gives her a burst of energy to bust them.
Perry goes into his lair using the refrigerator and ends up going down an icy chute, freezing him in a glass of lemonade. Major Monogram informs him that Doofenshmirtz has been spotted at the Danville Aqua Adventure water park with an insane amount of Doonkelberry oil. As soon as Agent P departs, Carl uses a leaf to fan Monogram to keep him cool.
She attempts to get her mom to see the boys' invention, but waits a minute to let her finish washing the dishes. But the ice wheel rolls out of the backyard just in time for Mom to not see it. So Candace mounts her bike and chases after the ice wheel.
When Perry reaches the water park, Doof is already there and traps him in a wristband. Doof explains his plan to Perry via backstory. Back in Drusselstein, everyone had fun at the Doonkelberry oil water park, except for Doof, so he will use his latest creation, the Dry-It-Off-inator (which is actually made from Vanessa's hair dryer) to dry up all the water in the park and replace it with slippery Doonkelberry oil.
As Candace follows the gang on the luge wheel, her bike gets stuck in melted fudge from a giant decorative fudge pop atop an ice cream truck. Candace uses the sticks from the fudge pop to turn them into makeshift skis. Through the song sequence, Candace skis the gang and gets a costume change into winter gear.
Back at the water park, Perry escapes from his trap. Doof gets a call from Vanessa, who is mad at her father for making her hair dryer into an inator. Atop the Hammerhead water slide, Doof zaps all the water out of the water park.
Candace calls her Mom to take 4th Street and the gang offer her a luge, which she refuses. A news van with Danville Today stalwart Dink Winkerson follows Candace and interviews her. Candace becomes more excited about getting 15 minutes of fame and waiting until the 4:00 news to show her mom. As Linda approaches 4th Street, she looks left only to find the luge wheel being blocked by a donut truck. She stops again to let a tortoise cross the street.
Back at the slide, Doof replaces all the water in the park with Doonkelberry oil, causing all sorts of commotion among the parkgoers who slip and crash. Perry ascends the fake mountaintop, but Doof spills some oil onto him. Perry uses his beaver tail to climb up the oil. The oil also causes the luge wheel to spin out of control, causing the gang to abandon ship. Doof fires his inator at Perry, but ends up drying Candace's lips, leaving her unable to tell Mom where she is. As Doof fires up the inator, he accidentally zaps the rope the shark is on, causing it to crash into the luge wheel, which goes up the slide and catapults Doof away. As the luge wheel reaches the sun, it melts, turning into rain and bringing all the water back to the park, and making the oil fall onto the Farmer and his Wife's giant salad bowl.
As Candace finally gets her mom, she sees the gang cooling off in the pool. As soon as four o'clock comes, Candace gets her Mom to a television, only to find her story has been overshadowed by the tortoise using Candace's makeshift skis. Perry then rejoins the group with Elvis-like hair, showing his version of defining cool.
