The coop is under construction and I'm reading up on breeds. We live in the high desert of southern New Mexico, where summer temps top 100 and winter temps can dip below freezing at night. At every temperature, the weather is dry,sunny, and often very windy. Now, the coop is designed to shelter from the wind and cold in the winter but also convert to be open and airy in the summer. I want hardy breeds with a good heat tolerance, but I don't want them to freeze their little nuggets off in the two months it's actually cold here. Suggestions?