There are places in Texas this summer where the water in the hose or cold water spigot that serves the house is too hot for showering. I shared a trick with a couple of friends that I learned in Arizona's Sonoran desert from park rangers stationed there. Turn off the hot water tank. Since it is in the air conditioned house it remains room temperature and can be used to cool the hot piped-in water for showering. If it's a really long shower it's over when the hot water that has refilled the tank hasn't had time to cool.