Kotatsu

A kotatsu (炬燵^?) is a low, wooden table frame covered by a futon, or heavy blanket, upon which a table top sits. Underneath is a heat source, often built into the table itself.^[1] Kotatsu are used almost exclusively in Japan, although similar devices are used elsewhere.

A person sits on the floor or on zabuton cushions with their legs under the table with the blanket draped over the lower body. The kotatsu was designed for people wearing traditional Japanese style clothes, where the heat would enter through the bottom of the robes and exit around the neck, thus heating the entire body.