Hot water bottle

A hot-water bottle is a bottle filled with hot water and sealed with a stopper, used to provide warmth, typically while in bed, but also for the application of heat to a specific part of the body.Containers for warmth in bed were in use as early as the 16th century. The earliest versions contained hot coals from the dying embers of the fire, and these bed warmers were used to warm the bed before getting into it.'India rubber' hot-water bottles were in use in Britain at least by 1875.Modern conventional hot-water bottles were patented in 1903 and are manufactured in natural rubber or PVC, to a design patented by the Croatian inventor Eduard Penkala. They are now commonly covered in fabric, sometimes with a novelty design.Hot-water bottles are meant to contain very hot fluids and also supposed to be in contact with human skin. It is therefore of the utmost importance to ensure, mainly through standards and regulations, that the closing and welding is stable enough to prevent burns, but also to make sure that the bottle’s chemical components are not dangerous for human health. More generally, it is crucial to certify and assure that hot-water bottles, whether manufactured, sold or imported, are safe.There have been problems with premature failure of rubber hot-water bottles due to faulty manufacture. The rubber may fail strength or fitness tests, or become brittle if manufacturing is not controlled closely. Natural rubber filled with calcium carbonate is the most common material used, but is susceptible to oxidation and polymer degradation at the high temperatures used in shaping the product. Even though the brittle cracks may not be visible externally, the bottle can fracture suddenly after filling with hot water, and can scald the user—sometimes requiring hospitalization for severe burn cases.Alfred, the cantankerous hot-water bottle, is a character from Johnson and Friends, a popular Australian children's television series from the 1990s. This character has gained a cult following in recent years, particularly among those who grew up with the series, due to the odd character choice. Alfred is believed to be the only anthropomorphised hot-water bottle in existence.