Springfield Pool Mobile is a giant truck with a pool as its carriage.
During the Springfield heat wave, Bart and Lisa hears the Ice Cream Man driving down their street. They run to it in excitement, but are disappointed to hear her was just announcing he had none left. Then a sound similar to an ice cream van is heard, they get excited, however it is a Chili Van attempting to sell chilli and ginger ale. Then the two are rewarded with Otto Mann bringing the pool mobile. Many children swim inside it for awhile, until Otto tells them they have to go. Bart attempts to stay underwater, but fails. Otto says they need to fill it with Epsom salt and get to the Springfield Retirement Castle. They ask when he will be back, and he says he is only budgeted for one day of the summer.