Public health has made our lives safer--but it often works behind the scenes, without our knowledge, that is, "while we are sleeping." This book powerfully illuminates how public health works with more than sixty success stories drawn from the area of injury and violence prevention. It also profiles dozens of individuals who have made important contributions to safety and health in a range of social arenas. Highlighting examples from the United States as well as from other countries, While You Were Sleeping will inform a wide audience of readers about what public health actually does and at the same time inspire a new generation to make the world a safer place. David Hemenway tells of energy-absorbing steering columns for cars that reduce the likelihood of severe injury in crashes, less flammable pajamas for children that prevent burns, rule changes in football that reduce spinal cord injuries, and design innovations for the Washington D.C. metro that brought crime down. His profiles of public health heroes include a surgeon who has helped make playgrounds safer, an eye doctor whose pro bono work has led to dramatic reductions in eye trauma, a member of the British parliament who has helped prevent sailors from drowning, and many more.