I can understand that... when i was on my journey in Poland (still regret for not visiting CDPRED HQ ^^) it was somewhere around 0-5 degrees Celsius...it was hot for me for some reason, people were freaking out for me being comfortable while everyone were shaking. (The people who were with me).when i was living in Tokyo it was around 10-15 degrees celsius during the winter months, and because I am English I found it pretty warm, so I was dressed normally in a t-shirt and/or shorts. All my Japanese friends and teachers freaked out and said I would catch a cold if I didn't wear a coat and scarf.
I didn't think the UK was particularly cold compared to other places but Japanese people in Tokyo really can't handle cold weather. However they do fare much better than me in their summer, where I thought I was going to die from heat exhaustion every time I went outside.