Yeah chic I really think it would be acclimatisation. Same as us stupid mammals lol. Across Australia you can usually tell the tourists, even without hearing their accent, by what they’re wearing lol. One time I went to the Australian Open (Tennis) in Melbourne and the pilot announced the weather as we were coming into land. 40 degrees. The whole plane groaned audibly lol. We got off the plane, and in the shade, it honestly was like a 30 degree day here, because the Southerners just don’t have the humidity we have up here, which we thought was really pleasant
In the southern states they either get wind off the Antarctic or out of that little desert that makes up most of our continent lol, and if that breeze changes direction, you can literally change 30 degrees in like, an hour!
But then again, up here in Queensland in winter we get the Annual Grey Nomad Migration (oldies in caravans from the southern states holding up the traffic on the highways lol) and when we locals are all still getting around in long pants and hoodies, they’re in shorts and shirts lol!