Hot and cold

I really don't get how some people could be outside with short sleeves and shorts in 45 degree weather. It's not extremely cold, but it is not warm enough for shorts and short sleeves especially with the inconsistent weather we have been having. One day it's freezing, the next it's nice, and the next it's windy and on top of that it is still flu season. Here in the east coast at my school, I've noticed that its always the white people wearing shorts and no jackets, and just about every black person is wearing a hoody or a coat. Maybe it's something in our blood hmmm lol