"HOKKAIRO" is the brand name which became famous first in japan.
Apart from dressing in warm clothes and trying to stay out of the cold, there is one more answer to staying warm in adverse weather. These are hokkairo. Hokkairo are small pouches that contain chemicals that heat up when exposed to Oxygen in the air. Hokkairo are inexpensive (about 100 - 150 yen per packet) and provide up to 8 hours of continuous heat. They also come in different temperature ranges, with the hottest hitting peak temperatures of 70C. Most operate at around 50 - 63C. Hokkairo are designed to be placed in a jacket pocket, however those people with poor circulation will be pleased to know that there are some hokkairo available that are designed to be placed in shoes to keep your toes warm. Some also come with an adhesive backing so that they can be placed on your back under a jacket.
The size of Pocket Heating Pad.
Reguler size is about 10cm × 15cm
Small size is about 7cm × 10cm
This is stick-on type.
Take out the patch and remove the seal,and to the body part over clothing without rubbing or squeezing the product.
You must not put it on direct skin or you burn yourself!
For use on the sole.
You can buy this in supermarket or drugstore.
To avoid burns to skin,
you must not attach Hokkairo to the direct skin, please use it very carefull.