I am more concerned with chickens that can take the heat. Most of the birds that we can get in the US are cold hearty, except for some of the fancy or bantam breeds. Chickens can keep themselves warm easily. Keep cool in a humid summer is a different story.
That is true, I didn't mention it, but it is a bit of a concern. In CT we do get a good few days over 90 but I have a pretty good set up for them, they are under trees in full shade all day & I have a fan in the coop. Plus I make ice for them & tray of water, etc if it's really bad. But yes, def a consideration.