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.
Map of Sleep Insufficiency: The map below depicts age-adjusted* percentage of adults who reported 30 days of insufficient rest or sleepâ  during the preceding 30 days. * Age adjusted to 2000 projected U.S. population. â¡ Includes the 50 states, District of Columbia, Guam, Puerto Rico, and U.S. Virgin Islands.