The Japanese kotatsu combines a table, a heater, and a layer of comfortable blankets.
Traditional Japanese houses are not very warm. Some lack insulation, double-glazed windows, or central heating; the wood and paper partitions that divide rooms don’t keep much heat in or cold out.
(Traditional New Zealand houses, by the way, share this problem. Not the partitions, but everything else. Insulation wasn’t compulsory until 1978, so the country has a whole swathe of cold and damp houses.)
One of the Japanese solutions to a cold home is the kotatsu. This unassuming piece of furniture dates back a few hundred years in one form or another. But the modern form has four basic components: a table, a separate tabletop, a heater, and a blanket.
Start with a low table. Attach an electric heater to the underside of the table. Drape the whole thing in a heavy blanket, which traps the warmth from the heater. Attach the tabletop to the top. Now you can sit at the table, stick your legs under the blanket, and enjoy.
This blanket heater table, as you can imagine, is a perfect haven for sleeping cats. And some people fall asleep at the table with their legs still stretched out underneath, which sounds ridiculously cosy and/or dangerous to me. But hey, not as dangerous as an earlier version of the kotatsu. Instead of an electric heater, that one used a charcoal brazier set into the floor beneath the table. This setup dates back several hundred years, and no doubt involved more than a few singed heels.