In the same way that certain chicken breeds are better suited to cooler temperatures, some breeds are better for areas of the country known to exceed 100 degrees F.
In general, small, miniature-sized chickens called bantams do well in high temperatures. Chickens that are larger and have a lot of feathers tend to have a hard time weathering the heat. Some notable hot-weather breeds include Jungle Fowl, Blue Andalusians, Naked Necks, Golden Campines and Cubalayas.
Even if your birds stand up to the heat well, it's important to keep the coop and their water source clean, cool and fresh. Feeding them frozen fruit like watermelon or grapes is a great way to keep your avian friends content during the summer.