How to Stay Warm During a Japanese Winter (Part 1): Enter the Kairo

By Donnie | Articles


I don’t hate winter, but let’s just say it’s my least favorite of the four seasons. Even during Japan’s summer heat and extreme humidity, I would always say “Yeah, it’s really hot out here, but at least being too hot, isn’t as bad as being too cold.” To me, being the Georgia boy that I am, walking around in the cold is about as much fun as having a monkey double fisting handfuls of feces at my head. Not cool…not cool at all.

So today, let’s take a brief look at a cool, inexpensive, Japanese item to keep you warm this winter season: enter the kairo!!

Different types of kairo.

What is a kairo? A kairo is essentially a small heating patch or packet. Kairo essentially come in two main forms: haru (貼る (adhesive type)) and haranai (貼らない (non-adhesive, pocket type)). Both are pretty effective, but for some reason I find the pocket type to be significantly warmer than the adhesive kairo.

How long do they last?
It funny. I didn’t really know the answer to this question until about two days ago. I decided to take bike ride to Mount Tsukuba, and put kairo in my gloves and shoes to keep me warm during the ride. The kairo lasted the entire length of my trip which was over 2 hours total. I left the kairo in my gloves by accident, and the next morning, they were still generating a faint amount of heat. So for the price, they are a STEAL!

How much do they cost?
I bought a 10 pack of mini kairo from my local convenience store for 280円 the larger kairo 10-pack costs only 360. Not looking to buy a pack? Well the individual kairo are even cheaper, they cost somewhere between 25 and 75 yen depending on the size.

I thought I’d post a little video about a neat, inexpensive item to help keep you warm this winter. Check it out!

See you next time,

Donald Ash

About the Author

  • Vivian says:

    there are resuable ones too.

    pop in microwave oven.

    long run economical. and better for the environ.

    never used kairo til i got to japan.

    useful but overused here if you ask me.

    just deal w/it.

    kids are so weak and like sissies now. gotta make em tougher than they are turning out now….

  • Yeah, the kairo were a great discovery for me as well and a lifesaver during the cold winter months at school with no heating. I used to pop one in my pocket and it would last all day 🙂

  • Alana says:

    I had only used that haru kind before. The mini ones are perfect. But, when I went to China in December, I bought the haranai kind by mistake. They take longer to heat up, but give off more heat. They also lasted for two days! But if you are putting it in your pocket instead of under a layer of clothes, it doesn’t keep you as warm. Lower back is the best place to put a haru one. It spreads the most heat to your body (according to the TV). I ended up putting the haranai type in my pants but obviously it didn’t stay put. NG!

  • thanks for sharing this useful information. can’t wait to visit Japan this March and will definitely consider using kairo for the shoes as I’m not really used to cold weather.

  • Janet says:

    Thanks so much for explaining the differene between the sticky and non-sticky types! I’m currently in Japan and was having a hard time figuring out which ones were adhesive but your video really helped!

  • >