Aren't you hot?

Something I have noticed and do not quite understand is how Romans dress in the extremely warm weather compared to Americans. I sweat just from looking at people who look remotely uncomfortably hot while walking down the cobblestone streets of Rome. I can not comprehend or understand why and physically hot when it is over eighty degrees out they continue to wear long pants and shirts of dark colors. I have come to accept them for it and realize it is a part of their culture, but I will never get what is going on in their heads because I could never dress the same in this kind of weather. In the United States we are so acclimated to wearing as minimal clothing as possible in intense heat, and flip flops are always a must. However, when we wear flip flops in Italy we are always looked at as a “tourist” and sometimes that is the sole factor of determining you as one. I do not think I could ever get used to the clothing worn in the heat.