This is what happens on sunny days. The juveniles and adults take the shade and all the chicks just roast in the sun. A few sneak in because the birds are a lot more tolerant of each other when it's hot.
The chicks give themselves shade too. They balance on their legs, lift their feet off the ground, and keep their feet in the shade. Their feet have a lot of blood vessels so they like to keep them off of the warm ground where the breeze can cool them off.