Tuesday 19 February 2019

Staying Poka-Poka in the Japanese Winter: The Wonder of Hand Warmers

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Traditional hot-water bottle
Tokyo experienced its first proper snow last week, but it didn't stick and was pretty much gone by the next day. Nevertheless, it's been pretty cold though nothing  compared to Hokkaido which is experiencing a record cold spell with temperatures dropping below minus 20 (the cold front even spread to Hawaii where it was responsible for an unheard of snow fall in the low lying areas!). At least people in Hokkaido enjoy central heating though - the rest of Japan lacks this luxury. In the absence of central heating, Japanese typically heat only the living room in winter; this can make a trip to the toilet extremely chilly! For heating, as discussed before, kerosene/paraffin remains common and a kotatsu low-heated table highly recommended. At night, as in the UK, Japanese will often sleep with a hot water bottle in the winter - in Japan this is called a yutanpo (湯たんぽ) and is traditionally made from galvanised steel or hard plastic (pictured), though recently the Western style soft rubber type has become more common.

But venturing outside usually means walking: Japan, at least in the populated areas, is a public transport not a car based society and Japanese have been shown to be one of the most active people in terms of daily steps taken (something also linked to low levels of obesity). Now this means a lot of time spent in those cold spaces between home, station, and workplace - which is where the fabulous disposable hand-warmer comes in. Usually written in katakana as カイロ (kairo), these thin pocket heaters are commonly used not only during commuting and shopping but also in various outdoor activities such as skiing and hiking. Depending on the size, once in contact with the air they can last anywhere from 7 to (incredibly) over 18 hours at relatively high temperatures as the table below shows:
Table showing different types of and stats for kairo or hand warmers produced by the Co-op (生協)
As the table indicates, there are two basic kinds of kairo: sticky (haru=貼る)and non-sticky (haranai=貼らない) which are written prominently on the front of the packet (pictured). The former can be stuck over inner-clothing, like T-shirts and vests, or inside jackets while the latter are more for pockets and holding directly. As the table also shows there are special kinds of sticky kairo especially for socks (pictured). These packets will often contain the onomatopoeic word for pleasantly warm or comfortably hot, pokapoka or hokahoka, though the latter is more closely associated with steaming or piping hot food (indeed, Hokka-Hokka Tei is the name of a popular take-out bento chain).

Like the yutanpo traditional hot-water bottle above, kairo were originally metal vessels with hot stones, sand, or charcoal inside: see here for a little history and some nice pictures. Finally, this wouldn't be Japan is there wasn't a long list of chūi (warnings) about how to use kairo safely. These include not putting them directly on the skin, sleeping with them, or attaching them to pets! You have been warned...