Not sure what it was exactly that made the word ‘Hokaron’ pop into my head. Maybe it was connected to Saturday morning’s local forecast for cold weather. It’s not very likely that the recollection would come at a time other than winter since Hokaron is a cold season product. The word refers to a brand of pocket warmer popular in Japan and there at least, about as common in February as caps and gloves. I wasn’t sure whether a similar product is available outside of Japan, but pocket warmers are a lot more prevalent worldwide than I first thought.
Chemical pocket warmers are popular with many living in cold climates, but especially so for those who ski, snowboard, or work outdoors for long periods. These lightweight easy-to-use warmers are a great way to keep hands and feet warm. They are sold in a variety of shapes and sizes and all work pretty much the same way. Just tear open the cellophane bag exposing the warmer to air and presto—instant warmth that lasts for hours. Put one in each pocket to keep fingers from getting numb, or choose the kind that fit in the soles of your boots. I have even known older people in Japan to use them for relief of arthritic pain.
Hokaron pocket warmers work through a chemical reaction similar to rusting that occurs when they are exposed to air. For that reason, keeping them unopened until needed is vital. The warmer is composed of a mixture of iron, water, cellulose, vermiculite, activated carbon and salt inside a cloth-like bag. When the iron is exposed to oxygen in the air, it oxidizes. In the process heat is created. The salt acts as a catalyst and the carbon helps disperse the heat through the warmer. The vermiculite works as an insulator, keeping the heat from dissipating too rapidly. This chemical reaction occurs slowly enough to allow the heat to last for hours, but gradually the iron converts to iron oxide and the warming process is exhausted. On a cold day, this simple chemical reaction can do wonders for cutting the edge off winter’s cold.
Very popular among the Japanese, the idea of a modern pocket warmer grew from the early practice in Japan of heating rocks and placing them in a pocket. As the years passed new methods were invented which eventually led to a chemical pocket warmer developed in 1978 by Lotte Health Products Co. In 1989 they came out with a type that sticks to the body. Today the Lotte Hokaron series of warmers is one of the most well-known in Japan. The average warmer measures about five inches by four, maintains a temperature of between 154° and 129° F with some types lasting as long as twenty hours. The makers will tell you that, but I can’t say that in my experience one Hokuron pocket warmer has ever lasted as long as that.
A closing note about Lotte, the company that manufacturers Hokaron—It was founded in Tokyo in 1948 by Korean businessman Shin Kyuk-Ho, also known by the Japanese name Shigemitsu Takeo. And the interesting part—the source of the company’s name is neither Japanese nor Korean, but German. The founder was so impressed by Goethe’s 1774 novel The Sorrows of Young Werther, he named his newly-founded company Lotte after the character of Charlotte.