Pacha and Chicha young

Pacha with his wife Chicha in their youth

Cool Summer is an episode from The Emperor's New School. Kuzco planned to stun everyone as cool king of the beach on holiday, but Pacha forces him to dress sensibly and put on lotion, so he wants to dump the family. Kronk accidentally discovers a fountain of youth, which Yzma abuses to seduce Kuzco as a girl, but it wears off and Kronk spills some water in a beach fountain. Thus Pacha gets rejuvenated, also temporarily, actually making Kuzco a surprise hero.