It's dangerous, yeah. Not saying you couldn't do it, but it's a risk. Here's some advice from an on and off insomniac:
The first 48 hours are easy. After the first 24, your body will likely compensate with an adrenaline surge, and you'll feel like a million bucks. The struggle comes after this mark.
Eat and drink. A lot. Your body is going to need the extra fuel without its natural hibernation mode.
Hallucinations, voices, sounds, document them. Write them down, draw them, whatever. It'll keep you grounded in reality.
Eye drops. Get some. They'll make the experience just slightly less hellish. Your eyes are going to burn red and become agonizingly aware of the little impurities in your eye fluid.
If you're planning on doing this with the help of a caffeine overdose, drink equally as much water. Caffeine revs your system and dehydrates you. Dehydration is not something you want, especially when you're already going to be putting your body through this kind of trauma.