Can you get Gatorade, or Powerade? Either works. I also pour a bottle of it into their water buckets, then add the normal amount of water. Shade, make a big wet spot on the ground, with a hose. Be careful to make sure you run the water long enough that it's cool when coming out. Water sitting in a hose can be very hot when it first comes out. You can set ice cubes in the wet spot to make it nice and cool.