This document discusses fatigue in the context of military and non-military 24/7 operations. It defines different types of fatigue such as circadian, acute, cumulative, and chronic fatigue. It describes shift work sleep disorder and discusses the fragility of sleep. It also summarizes a simulation model called SAFTE that models fatigue effects and discusses fatigue countermeasures such as sleep hygiene, napping, caffeine use, and stimulant medications.

1. Fatigue James C. Miller, Ph.D., CPE Miller Ergonomics, San Antonio, Texas Air Force Research Laboratory (retired) [email_address]

12. Fragility of Sleep

23. Schematic of Fatigue Model

24. Validation Example

26. FAST TM Cognitive performance (%) Cursor for I/O “ Dashboard” Sleep (blue; model input) Work (red; captures data output) Daylight/darkness (gray) Circadian phase (thin red curve)

31. Forensic Fatigue Risk Factors

40. Tactical Caffeine Use

45. Modafinil Caldwell & Caldwell

46. Dextroamphetamine Caldwell & Caldwell

48. 30-Hour B-2 Missions “ Our 100 percent success rate of ALLIED FORCE missions is directly attributed to the support of the SUSOPS folks at Brooks.” (specifically, Dr. WF Storm) - LEROY BARNIDGE, JR., Brig Gen, USAF Commander, 509th Bomb Wing