Bill Ragan, M.S. said that circadian desynchronization was one of the causes of several aircraft accidents over the years. While the exact cause of these accidents was hard to pinpoint, many of them were linked to human error. Lag: A Look at Circadian Desynchronization (ISBN 978-1-4357-0221-9) was focused on stress that resulted from jet lag, shift work, and fatigue in aviation. Many of the principles included here transfer over to other industries like commercial overland transportation, law enforcement, and healthcare. How much does fatigue cost you? Only the reader will know, but factors that can influence the costs were discussed in this book. Not intended to be a substitute for a consultation by a provider, some interventions intended to help lower the cost of fatigue were included, as well.