(HealthDayNews) -- Remember nap time when you were a small child? You might still need an afternoon nap to refresh you.
Sleep researchers cite the "midday trough" -- the period between 1 p.m. and 4 p.m. -- when people lose energy and feel sleepy. This time period also has a significantly higher number of industrial and traffic accidents than at other times. A parallel trough occurs between 1 a.m. and 4 a.m., when humans are most likely to die.
Many countries in Europe and South America build a leisurely lunch followed by a rest before returning to their business schedules. But not in the on-the-go United States.