I had not known that the word "futon" is an English word until I looked it up on my online dictionary.
The fact that Wikipedia has a page to explain futon in English surprised me.
A futon is a traditional blanket that is used in Japan when we sleep. It makes us feel warm and promises a comfortable night. I love a bedtime with a few layers of futons, especially in winter, because it is freezing cold in Japan. You may recommend that I can use a heater instead of futons, but I do not like using heaters while sleeping. All night heaters sometimes make me feel uncomfortable in the throat when I get up.
I tried wearing a mask with heaters, but no improvement was obtained because I felt I could not breathe well during sleep. Such a kind of problem can occur when I stay at a hotel.