Water Slides, Hose Pipes and Wild Swimming

S1, E6: It's a very hot day and Sky and Finn coming up with ideas to stay cool and have a lot of fun at the same time. Finn has the idea of playing on a water slide in the garden. Sky and Finn also have a hosepipe fight with daddy. Afterwards Sky and Finn go to the river for a swim. How do you stay cool on hot days?