“If that’s not a minhag I don’t know what is.”
OK, you don’t know what a minhag is.
The point with the turbans is that formal wear always defies climate. If you really didn’t want to sweat, you would wear shorts and short sleeves. Whether you’re wearing Arabic formal attire, European, or Chinese, you’ll probably be warm. That’s just how the world works.
These discussions used to pop up a lot more in the CR. Usually just comes down to someone not entirely comfortable in their own shoes who gets insecure around people who are more frum, so they pick on superficial things like attire as a coping mechanism.