I've done about 40hrs without sleep, was up for work at 5am, did usual day,had to go to hospital with wife on the evening, was there all night, turned out she was ok, so went straight to work in the morning, finished work at 4pm, got home about 6pm, had dinner went to bed about 9pm. wasn't that hard as i was occupied most the time, couldn't do it just for the sake of doing it.