I'm pretty sure they would get way too cold as there are 6 windows total and we get pretty windy here. There are only about 6 weeks of real warm weather (80 or over at high). I'm more concerned with cold weather and wind/snow in the winter. The coop has open gable ends for ventilation.
Sounds like you have thought about it. The heat can take them out much more quickly than the cold.
I would certainly not have them open in the freezing weather, necessarily ; thus the polycarbonate covers.
But I'm going to bet that you'll want those windows open in the summer if the sun hits them directly.
But shade cloth or lattice work over them will help as well if you leave them intact.
Edited by lynnehd - 3/9/16 at 9:01pm