In Kyoto and many areas in Japan, you wear 3 or 4 kinds of clothes even at home in winter, for example, underwear, a shirt, a sweater, and a cardigan if you want. Our houses are built for humid and hot summers. A lot of Western students do not know this and say, "How cold!!". If they contact me before the first winter, I can tell them that in advance. But afterwards....they just catch a cold. I'm so sorry!