What do you do if you haven't gotten any sleep and you have to go to work?

Well, asking why you did that even though you knew you had work the following day wouldn't solve this predicament.. We've gone through such situations before and the dilema is indeed troubling. All we could do is just get it over with as much as we can and catch up on some sleep when we do finally get the chance. Coffee doesn't work on you as you said. try eating heavy meals so your stomach would be forced to digest them. Then again, some people get more sleepier with that compared to others, include me, can't sleep with a full stomach. Of course, you'll remind yourself of that the next time something like that seems to happen again before hand, right?

well, if you dont have any choice, you really have to go for your work.. but take time to get some nap (of courts whenever your boss isnt around).. a good sleep is very essntial for us humans, so when we arent able to get some sleep, we lack energy.. just like cellphones, we too have to recharge ourselves through sleeping..

Try doing some light aerobic exercises. You might feel a big more invigorated.