People are physiologically programmed to sleep during the night and be active during the day. This is known as the sleep-wake cycle. Consequently, shift workers are especially prone to sleep disturbances, sleep deprivation and misalignment of the sleep-wake cycle, all of which lead to sleepiness, fatigue and associated performance deficits.
People don’t fully adapt to shift work. This is particularly true for evening work, night work and rotating shift schedules. For example, night work requires restorative sleep during the day which is often shorter, lighter and less restorative than nocturnal sleep.
Most shift working industries are required to identify, assess and control fatigue as part of their health and safety management system. This is no simple matter, particularly for personnel working in hazardous environments or performing safety critical tasks, such as heavy vehicle operators in the road transport or mining industries.
Even the best designed fatigue management plans cannot regulate sleep behaviors during rest periods or days off. Insufficient restorative sleep will increase levels of fatigue with each consecutive shift. This can be further exacerbated by rotating shifts due to the changes and disruptions in sleep/wake patterns during changeover periods.
An effective fatigue management plan should offer strategies to counteract fatigue. While the only true cure for fatigue is sleep, shift workers will need to rely on naps to maintain alertness, and caffeine can be effective to some degree depending on the individual. But keep in mind that these will only reduce the risk of a fatigue-related incident, they cannot eliminate the risk.
Technology that can objectively detect the early signs of fatigue in real-time can be used to effectively complement organizational and regulatory approaches to improve fatigue management. The ability to continuously assess operator fatigue, regardless of factors such as time-of day (sleep-wake cycle), previous amount and quality of sleep, effect of drugs or alcohol, or undiagnosed sleep disorders, would be beneficial to any fatigue management plan.