One challenge is that so many Americans live in climates that humans don't really belong in, and thus rely on air conditioned cars & buildings. 29 million peopl

One challenge is that so many Americans live in climates that humans don't really belong in, and thus rely on air conditioned cars & buildings. 29 million people live in Texas, 22 million in Florida, 7 million in Arizona, 5 million in each of Louisiana and Alabama, 3 million in Nevada, etc. Walking anywhere when its high-humidity and over 90F (33C) isn't workable for most people because they don't want to arrive covered in sweat. And that's not a temperature that is a brief high for the day at 3pm, it's that hot at 9am on the way to school/work and still that hot at 6pm when headed home.