MYCOAL:Footwarmar

Simply open the outer package and immediately place insole inside any pair of closed-toe shoe or boot. Foot Warmer insoles are specifically designed for use inside a shoe or boot where oxygen is restricted. Do not use in ventilated type footwear. For best results, insert each insole forward to toe of shoe or boot. No Trimming. No Peeling. Fabric side up, white side down.

*With bare feet or sheer hosiery
*with sandals or open shoes
*On parts of the body other than the feet
*With infants or small children
*On bruising or swelling
*Infected areas, frostbite or desensitized skin
*While sleeping

Children, the elderly, the handicapped and those unable to remove the Foot Warmer by themselves should be supervises when using this product. Persons with diabetes, poor circulation, nerve damage or paralysis should not use expect as directed by a physician.
Remove the Foot Warmer immediately if it becomes uncomfortably hot. If used incorrectly, higher temperatures may occur, coursing burns. This product is not designed withstand the impact of running or jogging.

For EXTERNAL use only. Do not puncture the Foot Warmer or allow contents to contact eyes or mouth. Consult physician if swallowed.

By reacting with oxygen, it occurs due to the iron oxidization of chemical reaction.
Actually, when the iron oxidizes, (iron rusts out), the heat called Reaction Heat is generated. In our daily life, the reaction occurs very slowly so that we cannot feel it, but the warmer makes all kind of efforts to make good use of the Reaction Heat.

There are all kinds of materials used in the warmer. Combining with one another, it warms up.
Iron powder…Caused when iron oxidizes
Water…Used when iron powder oxidizes
Salts…It hastens the oxidation of iron powder
Activated carbon…Absorbs oxygen in the air and increases the amount of it
Water retention agent…Retains water for oxidation.

The warmer root dates back to the EDO period. People of theEDO period warmed body inserting a stone into their bosom. Entering the MEIJI period, a stuffed pulverized hemp stalk into a bag, burnt kneaded hemp stalk in the vessel (charcoal system warmer) began to appear.
In the Taisho Period, a (Benzine system) warmer appeared. Utilized catalysis of vaporized gas of benzine . At the beginning of the Showa period, the current warmer utilizing iron powder using oxidative pyrolysis appeared.