In the early 20th century, before central heating was common in houses, some rooms (especially those farthest from the chimney) were cold. If you wanted to warm the bed sheets before hopping in, you could fill a bottle like this one with hot water and run it over the sheets. It could also be left in the bed as a foot warmer. The Palco Aluminum Hot Water Bottle was manufactured by Worcester Pressed Aluminum Company, which also made canteens and syringes. A cork stopper fits tightly in the neck of the bottle. Stamped in the center of the bottle is a wreath and in the center of the wreath is 鈥淧alco Worcester, Mass. Patents Appl鈥檇 For鈥. This hot water bottle is missing its flannel bag cover.