People who have had chickens for years know that it’s the heat you should worry about, not the cold. A chicken can die in severe heat. It will happen quickly. You know that the hens are struggling when they have their beaks open and are panting. You know they’re in trouble when they are listless and not drinking. There are some things you can do for your chickens so that you don’t have to bring them into your air-conditioned living room.
First of all, chickens must have shade. If you can’t site your coop in a shady spot, put a shade awning up. We have a large rectangle of shade fabric over the bunny’s hutch (rabbits are even more susceptible to heat stroke than chickens) that the chickens also like. We bought our shade tarp on-line. A web search should turn up what you need.
Provide a shady area with loose dirt where the hens can take dust baths. They’ll wallow down until they get to cool soil. Also, keep a waterer in the shade. If it’s really hot, the hens might not go across the sunny ground to get to the usual waterer in the coop. I fill the outside waterer with ice cubes, and as it melts the hens have cold water to drink. When it gets really hot, I’ll dump a pile of ice cubes in the run.
I always have a chicken or two that goes broody in the worst of the heat and insists on staying inside the stuffy coop inside of a metal, even stuffier nesting box. After having no success getting them to go somewhere more comfortable, I’ve finally given up and hung an old box fan to blow air on them.
I know people who live in hotter climes than here, who provide misters for their chickens, and cool off their coops by spraying water on them.
Just don’t assume that your chickens can figure out how to get through the hot day on their own. Give them areas that they can cool off in, and make sure they go there!