Effects of night work on circadian rhythms and sleep.

1. Night time is physiologically unsuitable for humans to work. 2. Night workers often suffer a drop in alertness between 2.00 am and 4.00 am. 3. If patient safety and nurse account-ability are to be maintained, nurses working at night must overcome this drop in effectiveness. 4. Periods of 'flash sleep', and taking the main rest period in the afternoon can counteract the effects of night work on the circadian rhythms.