Dealing with being tired?

How is everyone dealing with being exhausted I woke up to go to work this morning around 5am it's currently only 9am been at work 1 1/2 hours and I'm having the hardest time not falling asleep sitting standing in other words I'm sooo tired. Luckily I am a nanny so when he naps after lunch I nap till the oldest gets home from school. Window people are coming today to replace two windows so I hope I get that nap. How is everyone dealing with this fatigue? Any tips to not feel like your eyes are going to close any min now. I've had high energy so far but the last couple days my body has been telling me to sleep.