You need immediate alertness. Try a “ caffeine nap. ” Researchers at Loughborough University tested several ways to improve the alertness of drivers and found the “caffeine nap” to be the most effective method. You down a cup of coffee or other caffeinated beverage and then immediately hunker down for a 15-20 minute nap. Again, don’t go any longer than that or you’ll awaken with sleep inertia. The caffeine clears your body of adenosine, a chemical which makes you sleepy. It takes awhile for the caffeine to circulate through your system, so it doesn’t effect the quality of the nap. Instead, it kicks in in tandem with the refreshment you would feel upon awakening from a normal power nap. I’ve personally found the caffeine nap to be effective, especially when you’re crunched for time; it’s easier to get up and keeps you from the temptation of turning a 20 minute nap into an hour and a half session.