Almost everywhere, AC is truly a luxury.
Stay out of the sun, sweat a little, you'll be fine. Arabs have it much worse.
In humid places, however, sweating is almost useless and you can suffer in mere 90F heat.
The other important point is that somehow folks in Singapore manage to survive, but in Singapore there's never any winter. I once heard a physiologist remark that humans can adjust to a wide range of temperatures, but it takes a few days for the body to reprogram itself for freezing ambient temperatures after spending months in roasting ambient temperatures. That's why the first few days of cold weather in the fall and winter feel really cold and everyone dons parkas, but when spring rolls around the exact same weather feels really warm and everyone puts on their shorts.
So maybe if I set out to live without A/C I'd get more used to it after a while. But the first few days are a killer, and at some point one just gets sick of being listless and warm and starts subconsciously looking for excuses to visit nice air-conditioned buildings.
I noticed this empirically with myself whenever I traveled from California to Sweden in the winter. Coming to Sweden, I'd be cold all the time for the first couple of days, and then back in CA, I'd have hot flashes for a few days there. Nice to know that I wasn't imagining things. :)
Fahrenheit. (It doesn't seem to be true that he intended 100 degrees to be human body temperature. It's possible that he specifically wanted the difference between body temperature and freezing point to be (a power of 2) degrees.)
I won't trade it for Phoenix until I turn 65. But yes, it does make heating, cooling, clothes shopping, and a host of other things a little more difficult than the southern states.
Thanks!
Passive cooling, by contrast, is pretty much adequate (though that's not to say the heat can't kill you if you're out in the sun.) But in any case, when you look at the amount of energy expended on heating, the modest amount expended on cooling is a natural expenditure. I think in general that's why a lot of colder countries like Norway are more rich and prosperous than their warmer counterparts. When it costs $30,000/year just to survive, luxuries start to become a lot less costly as a percentage of income.
I'm guessing the author hasn't lived in Minnesota. For one thing, the temperature differential is much higher than in Southern States. It may reach 110 degrees F in Phoenix, but it almost never drops below 32 F. In contrast, Minnesota gets temperatures from 0 F to 90 F.
There's also the question of energy use. The Minnesotan winter makes a huge amount of energy (for heating) an absolute need for survival. When you're used to expending all that energy 4-6 months out of the year, using a much smaller amount to stay comfortable when the temperature peaks above 80 F or so is not an incredibly noticeable loss.
When some sort of active climate control is a requirement for life, it's unsurprising that Minnesota did it first - since AC is more a luxury in the Southern states, even though the heat can kill you if you don't have some sort of effective cooling.