AJN, American Journal of Nursing:
Taking naps is a great way to become more alert, well rested, and rejuvenated. According to this article, "several hospitals have policies allowing naps and areas where nurses can take them," but I'm not aware of any in my state, California.
Hopefully these policies will be implemented nationally by the time I graduate from nursing school. Allowing for a rest period during a shift will make for happier and more alert nurses, thus creating a safer environment for patients.