I was reading today's post from Wendy's "Surviving the Suburbs" blog about staying warm in a cold weather. Here on the island, we do have weather cold enough to be dangerous, although thankfully, it doesn't last quite as long as it does in Maine. She mentioned the use of a kotatsu to provide on-the-spot heating for people sitting down to a meal. Being a curious sort, I began researching it on the internet.
It seems that some folks even take a nap under the blanket of the kotatsu, and I can imagine hubby doing the same thing, so Wendy's concerns about the carbon monoxide from a wood or coal-heated kotatsu is a good one. I read another post about the use of the kotatsu, and other common effects of cold weather as experienced by Amy Chavez in Japan. Cold is a very difficult thing to live with as a constant feature. In many ways, it is like being in constant pain.
Wendy's idea is to heat rocks in a grill outside while cooking a meal, and boiling water, and then to bring these inside. Considering that even when you have a warm coat or sweater on, your legs and feet still get pretty cold, this is a smart idea. Interestingly, ehow.com has an article on how to build your own kotatsu, although it uses an electric heater.
I noticed when looking at images of the kotatsu in use on the internet that many people have high-backed bed-seats, and that the blanket drapes around the sides of it so that the back doesn't get chilled.
Even if the electricity isn't out, as an energy saving option, this seems like a great idea. Another idea worth looking into is a variation on the Kang bed-stove. A modern version of this type of heating can be found in the book Rocket Mass Heaters, by Ianto Evans, and Leslie Jackson. You can read some excerpts from this excellent book at their website.