The hypocaust system. The hypocaust system (hypocaustum in Latin) was a heating system used in (wealthy) Roman homes and Roman baths, and the closest thing to central heating today. The hypocaust was a system that circulated hot air under the floor and surrounding walls. Hypocaust construction
CDC: Nearly 9 millon Americans use prescription sleep aids. Nearly 9 million U.S. adults take prescription sleep aids, with use more common among those who are older, female, white and better educated, according to the first government survey of its kind released on Thursday.
According to the American Insomnia Study, about 23 percent of American workers are sleep deprived, which costs the American economy $63.2 billion dollars a year in lost productivity. American adults lose about 11 days a year to insomnia and often go to work too tired to do their jobs properly.