The fact you are planning to do this makes me think you've done it before, since based on this study....

http://www.bbc.com/news/health-26630647

My ROTC buddy used to put tiny drops of hot sauce in the corners of his eyes when he was required to stay awake for prolonged periods of time

Start mastvrbating but don't finish and keep a semi. Works for long road trips no reason it wouldn't work for this. Also caffeine of course, I really like the white can variety of Monster (ultra?)

Since someone mentioned adderall I will go ahead and vote for cocaine, just make sure you have enough to last for the two days! (it's a joke, you can't buy enough for two days because you will do it all before the time limit is up, it's like moore's law or something)