I just want to say that graphs like this should be contrasted with the number of deaths from extreme cold. I know Arizona probably doesn't have the numbers of say, Alaska, but it's worthy of note to contrast the two.

I'd also point out that it is far easier for an individual to protect themselves against the rigors of cold than it is for heat; in the cold, with warm clothing, you can keep yourself warm, while the environment is very cold; fire is relatively easy to make, even if you have little more than sticks, and thus getting warm or keeping yourself warm is by and large easier to accomplish than staying cold.

When you're in an extremely hot environment, it's not like you can make yourself more naked than naked. You need some outside influence to keep you cool, like a swamp cooler, a misting sprayer, a cool body of water (like a river or lake), or some kind of man-made cooling device like an Air Conditioner, in a relatively sealed enclosure (which relies on consistent access to power to run it). most of these are either inaccessible to people in a city or built-up area; sure, there are fixtures, like fountains that contain water, usually not enough to keep them from heating up, and usually the water is recycled, so the heat stays with the water. all other water access is typically restricted to water lines, which usually someone is paying for, and nobody wants to pay to keep random people cool when they don't have to. All man-made (air conditioner) type cooling is generally access restricted to either workplaces, homes, or businesses/storefronts, where the expectation is that you'll be spending money there (which not everyone has).

I'm just saying, that the limiting factor to reducing death by extreme heat, is a far larger one, than death by extreme cold, where you should only need to hand out sweaters, gloves/mittens, jackets, blankets, etc, to keep people from dying from it. There's far-end extreme cold that almost nothing will save you from short of a heated structure, but generally, places that are inhabited by people who don't have access to safe heat and cooling (like a home), are more temperate than that extreme of cold.... not exactly too many homeless people walking around the arctic or Antarctic circles....

Neither is good, but both seem inevitable; regardless we should be doing all we can to help to ensure the survival of everyone, as a species. Whether that's saving them from the heat, the cold, from starvation or dehydration, we should be helping in any way we are able to.