I had just finished my F/E checkride that evening, my IOE instructor recognized that I was very tired and offered to take the trip out(I would observe). At top of climb the CA fell asleep with head on the back of his chair. The FO fell asleep with his head up against the glare shield and the SO (IOE instructor) kept falling asleep and almost hitting his head on the desk. I was the only one awake, but I didn't have a mic at the
JS station. Personally, I prefer that the naps are planned and one-at-a-time.