Kotatsu foot-warmers still a fixture in Japanese homes

A kotatsu is often seen in Japanese period flicks, where actors seated therein watch TV while they smoke or consume rice crackers or mikan (mandarin oranges). Basically it is a low wooden table frame covered by a futon, or heavy blanket, upon which a table top sits. Underneath is a heat source, typically an electric element, fastened to the underside of the table frame to project warmth in all directions. 

They are one Japanese home appliance that has never succeeded in carving out a significant market overseas.

The kotatsu subscribes to the principle of zukan-sokunetsu, literally keeping the head cold and the feet/legs hot. This is said to be especially conducive to students while they cram for university entrance examinations.

Westernization of Japanese dwellings and space considerations in urban residences has reduced the demand for these once-ubiquitous devices. In the "Be Between" online survey in the Asahi Shimbun (Jan 19), participants were asked if they used kotatsu. Out of 1,625 valid responses, 32% replied they did, as opposed to 68% who said they did not.

Still according to the survey, with 182 responses, the kotatsu was the third most common form of heating after air conditioners (500 responses) and kerosene stoves (289 responses). It was followed by heated flooring (169), gas stoves (159) and electric carpets (100).

The most commonly cited reasons for preferring not to use a kotatsu were: Other forms of heating are sufficient; once seated, one tends to avoid getting up; no space available for its placement; it occupies too much space in the room; and cleaning around it is inconvenient.

As for their benefits, users generally agreed that they are highly economical in terms of power consumption, don't require the user to refill tanks or mess with siphons, and that the chances of their causing burns or accidental fires are little to none.

Interestingly, 81% of the respondents who did not use a kotatsu said they had formerly done so, which would indicate a high portion of Japanese adults had used kotatsu at one point in their lives, but for various reasons abandoned them.

One user, a 46-year-old woman in Hokkaido, complained being seated at one tends to make people drowsy.

"I'd wake up and it would already be past midnight, and I'd look at the ceiling light still on and think, regrettably, 'Ahhh it happened again,'" she wrote.  

On a different tack, Shukan Asahi (Feb 1) warns that carelessness in use of a kotatsu can literally kill you.

"When you settle into a kotatsu, it is better to heat the room, and also use a humidifier to increase the moisture in the air," Dr Kimihiro Yoneyama of the Yoneyama Hospital in Tokyo's suburb of Akiruno, tells the magazine. "During summer it's said dehydration can make one vulnerable to strokes, but actually strokes are more common in winter. That's because sudden changes in temperature can cause blood pressure to fluctuate."

To avoid tragedy, the article issues seven precautions for kotatsu users. First, the room in which the kotatsu is placed should have a reasonable level of warmth and humidity. Those seated therein should drink the equivalent of one cup of water or other liquid per hour. It is recommended to get up and move around every 30 minutes to one hour.

Moreover, a kotatsu's thermostat should be set to the lowest comfortable position. It is advised not to sleep while seated therein, and a timer should be utilized to avoid overly long usage. And finally, one should not park one's body in a kotatsu following a bout of heavy drinking.

As a cold spell is predicted to hit most parts of Japan during the coming week, readers with a kotatsu at home might want to take the above precautions to heart.

© Japan Today