I am always on the search for unusual vegetables that like really hot weather. We always have really hot weather (some days above 100 and, recently, even a few days above 110). I think there have to be some crops out there from tropical areas that will do well but that Americans don't usually eat.
Some of the old standards I grow are: cowpeas (Crowder and purple-hull), sweet potatoes, okra, squash, melons, and peppers.
A couple of new ones I'm trying this year that seem to be doing well are Asian long beans (aka asparagus beans) and Malabar spinach.
Anybody have any other ideas?