Swimming pools are a cool and refreshing way to beat the heat on hot summer days. There’s nothing better on a hot day than jumping into the cool and rejuvenating water of your backyard pool. An evaporative pool cooler is a powerful way to cool your pool quickly. It’s like an air conditioner for your pool that works by using fans to cool the water flowing through the system. They are most effective when used at night to take advantage of cooler temperatures.