A Temperature Difference

I feel very cold when I am inside almost all of buildings in the USA, such as classrooms and restaurants. On the other hand, the outside is extremely hot. I am very uncomfortable about such a terrible temperature difference. American people make an AC work too much, so I almost freeze in the buildings. I do not see why it always happens. Are American people very sensitive to the heat? It is a mystery. Anyway, I am thinking I will bring a long-sleeved cloth to my classroom!