Winter in Tokyo

I catch cold. I have a sore throat. I'm too used to life in London. Winter in London is not so cold as in Tokyo, and it's very warm inside the house owing to central-heating during the night. But my bedroom in my parents' house in Tokyo has an air-conditioner. During my 25 years of life in Tokyo, I'd turn it off when I went to bed. So I followed this habit last night. I was wrong. It got really cold during the night. As I didn't sleep on New Year's Eve, got worn out by the 13-hour flight from London, and walked around a lot yesterday, I gave way to the flu virus... So I'm on bed all day today. What a waste of time in Tokyo!