To increase alertness, shift workers could consider a short nap before work.
According to circadian.com, the nap should be no longer than 30 minutes. Longer naps can result in grogginess.
Even if you can't fall asleep in 30 minutes, just resting with your eyes closed can help.
One trick for napping: Drink a caffeinated beverage immediately before your nap. This way you wake up more alert.
