I'm always on the lookout for veggies that will prosper in the heat. Most of these were in the ground, but I've seen them work in containers if they're large enough and don't overheat the roots (a common problem in pots). Here's what I can think of off the top of my head:

Leaf Amaranth - Delicious and incredibly easy to grow. Some varieties are also beautiful.

Swiss Chard and Kale - may test less than ideal, but won't bolt or become inedible like most brassica

Malabar Spinach - *beautiful* and very tasty, could care less about the heat. Easy to find even in the US.

Chaya - tree spinach, may take some work to find

Okra - the epitome of a sun worshiper. In last years century-record setting summer in Texas, Okra went gangbusters.

Southern peas - also called cowpeas, blackeyed peas

Yardlong beans - Asian green beans

Eggplant - loves the sun, though we're at the tail end of planting time

Gourds, melons, cucurbits - There are literally hundreds of options for good summer crops. Traditional cucumbers will become very bitter, but there are variety of Cucumis melo cultivars that taste like cucumber and never become bitter. These include the italian cucumber melon and the Armenian cucumber. Other asian cucurbits, like the "ivy gourd" or "bitter melon" are other great vegetables that absolutely adore the heat and have very few pest problems in the US. As for sweet melons, there are more than you can imagine. I'm growing Sugarbaby watermelons and American cantaloupes this year.

Sunchokes - a root crop with beautiful flowers, fit for anyone's front yard.

Sweet potatoes - start them now if you want a crop before winter.