They are very cheaply made and are weak. Build your own coop or get someone handy to make you one. Chickens share nesting boxes, I have 15 that share nests, but only use 2. But they often use a different two from week to week.
I have had decent luck with silver tarps that reflect heat, but it doesn't get that hot here in Kentucky. You might want to just cover the top portion to create shade and let the sides be open to circulate air through.
Chicks in Kentucky are sold out as soon as they get in the store. What is concerning is that chick starter is sold out as well which is tough on us that are hatching our own.
