Take a power nap.
"I'm a big believer in the power nap. I even took a nap in the backseat of a Humvee during a convoy in Iraq – at a time when every third or fourth convoy was getting hit by an IED. We had 20 minutes before it got dicey, so I set an alarm for 15 minutes. That morning, I found out that the convoy behind us was attacked." - John King, CNN anchor