Besides the risk of fire, it was recognized that the fumes from the embers were noxious. A doctor advised his readers in a publication of about 1790 to avoid bed warmers, or, if needed, replace the embers with hot sand. An alternative to the bed warmer was the "bed wagon" (, , both meaning "monk"). It consisted of a large wooden frame enclosing a bucket of embers, possibly with an iron tray and an iron roof-plate to protect the bed covers from direct heat. Pottery filled with hot water also was used. With the advent of
rubber, the
hot water bottle became dominant. In the early 20th century,
electric blankets began to replace the bed warmer. An alternative kind of bedwarmer in the mid-20th century in the UK was a pressed steel "flying saucer" or
lozenge-shaped device made by
Belling (established 1912), powered using an internal 40 W incandescent light bulb as a heat source. == See also ==