I used to work with a displaced Yankee fellow who wore uniform shorts and short sleeves year around. It would be 22 and sleeting and he'd be pulling a transmission with his bay door wide open while the rest of us were bundled up and freezing half to death. Seen the other side, too. When I was in college down on the coast there were quite a few Arabs in the Petroleum Engineering program and they would wear cashmere turtleneck sweaters any time it was below 105. I would be sweating and swimming through the humidity on the way to class and pass these guys on the sidewalk, they wouldn't even have a shine on their skin, but if it was 50 outside they were bundled up like Eskimos.