Other Types of Heating

Portable heat pads （カイロ, kairo）

You can buy cheap disposable heat pads in supermarkets and department stores - just look for the term カイロ （kairo） or ホッカイロ（hokkairo）. There are even sticky versions you can stick to the inside of your shoe or in between clothing layers. However, you should always keep a layer of clothing in between your skin and the kairo to prevent burns.

Hot water bottle （湯たんぽ、yutanpo）

These can be cheaply had from the 100-yen-store or supermarket, or you can buy higher-end versions that keep the water warmer. Stick one in the sheets of your futon.

Bubble wrap （バブルラップ, baburu rappu）

What’s the use of heating a room if the heat just flies outside? Tape over your windows with bubble wrap if your room is too drafty. You can find large rolls for sale online.

Don’t forget to dress warmly!

Wearing a cardigan or sweater will raise your body temperature 2.2°, wrapping yourself in a blanket will raise it 2.5°, and even just wearing socks will raise your body temperature 0.6°.

Reference:
Energy Conservation Center

• https://www.eccj.or.jp/dict/pdf/03_04.pdf（JPN only）（外部リンク）