Naps work

Researchers from John Moores University in the UK tested the effects of afternoon napping on sleep-deprived people. The subjects napped for half an hour just after lunch and then researchers measured their alertness. There have been numerous studies into the effects of power napping, but this one measured heart rates and reflexes as opposed to surveying participants. As per their hypothesis, alertness was significantly higher compared to the non-nappers.

From The complete guide to sleeping at work