Obviously those doctors and controllers don't have the time change to combat as well.
I have only suffered mildly before but this last rip to Thailand, going it took me a day or two to adjust, coming back was different entirely. We were well rested before the trip and the early morning start wasn't extreme, left the hotel after six, but for at least a week after we got back I was completely wasted. Three to four o'clock every afternoon I folded like a bad poker hand. I was just thinking, "How do those pilots do it?" I was doing some home plumbing and noticed that I was mis measuring, making mistakes and had become generally incompetent. Had to stop before I set the house on fire.
Frankly I did not have an opinion before, now I realise how serious it could be.