When it was very, very hot in the middle of the day there was not point in being out, and you could actually use that period to get some sleep so you needed less sleep at night.

BBC: How we go to sleep

"When people are entering a high-stress period, they don't sleep and don't exercise, but in fact, it should be just the opposite, " says Loehr.

FORBES: How To Run On Fumes

Vacations have been found to help us recharge -- we sleep better during them and for a period of time afterwards.

CNN: Take your vacation, or die?