For those of you who live where it gets in the 90s and up, you can create a simple 'swamp cooler' for your girls with burlap sacks and a drip hose.
Take burlap sacks and cut them open, stitch them together to form a tarp big enough to cover the cages. Run a drip hose over the top and right along the edge so the water will drip down and saturate the burlap. Shade cloth won't work because it doesn't get 'wet', the water just runs off.
The weave of burlap is open enough to allow some air circulation without stifling them inside, and adds shade too. When the warm air hits the wet burlap it will cool by almost 15 degrees on even the hottest of days.
This is how my neighbor kept her Angora rabbits cool when the temps hit the triple digits.