Circadian placement of sleep is also very important. Daytime sleep is typically 1.5 to 2 hours shorter than a nocturnal sleep period. REM and to a lesser extent stage II are the most shortened. This compounds the problems of alertness on the night shift. The night worker must contend not only with the expected circadian trough of energy and alertness, but also with sleep deprivation from poor quality daytime sleep.
Many shift workers develop a near obsession with sleep.
The social effects of rotating shifts on the worker and his family are also important. Society seems almost to actively subvert the shift worker. Neighbors insist on mowing their lawns while a night worker is sleeping. People who would never telephone at 2 am routinely do so at 2pm whether one is attempting to sleep or not. Education of the worker and his family is one of the most important strategies for coping with shift work.