Evaporative/Swamp coolers - A low tech option for keeping the heat down in dryer climates

This video shows how to make one kind of evaporative cooler. Evaporative coolers can lower the air temperature significantly in drier climates using evaporating of water across a porous surface. They're fairly easy to make with stuff you find in a hardware store and may offer some relief for folks who are facing record heat in places without AC.