In Chicago, it is frowned upon for unauthorized people to open up a fire hydrant. However, when temperatures peak at 100°F (38°C), neighborhoods come alive when someone lets the water flow.
On the first triple-digit day of 2012, I jumped in the car and drove to a neighborhood I saw several years ago with hydrants open. I was one block off from last time, but either way, the hydrant was open and the neighborhood kids were splashing through it.
Throughout the hour or so I hung around, various neighbors rolled up with a bucket of soap and washed their cars in the streets, while the kids ran and played in the cool, refreshing blast of water. Every so often, when no one was spraying down someone else, the same kid would come up and sit down directly in front of the hydrant.