Yeah, I definitely understand the heat issue. I grew up in the San Joaquin Valley, California, where the summers are also oppressively hot. Thankfully I'm living in Canada now, which is decidedly less hot (although it's far more humid).

I think it would come down to smarter, more localized urban design. For most of the history of human civilization, where we didn't have cars and air conditioning and the like, we had to be clever to carry out our daily life in a variety of climates. In hot, desert climates, cities were built more like this, building narrow alleys with tons of shade and designing for natural ventilation, keeping the whole city much cooler and more comfortable than the surrounding desert, even in extreme heat.

But what we have now is desert cities looking like Phoenix does:

An example of hot-climate urbanism done right (in Texas, no less!), however, is the San Antonio River Walk:

But yeah, these are more long-term things of course. But if we're talking about overhauling our car-centric urban design to allow people to walk to get groceries, we might as well talk about designing for the local climate, too.