As awful as Phoenix heat is, it has nothing on the humidity factor of Florida, or even the DC metro.
The worst thing about Phoenix heat, is that because land was so cheap, it is quite literally just a gigantic sprawling paved suburban hellscape.
Aside from the aesthetics, there’s so much pavement that it doesn’t cool down at night much at all. It just retains all that heat, right up until the sun comes up the next day.