Perhaps anxiety attacks is the answer, although he isn't afraid of flying. He just doesn't tend to sleep, and he always flying overnight. He has a very fixed biological clock ... always in bed at 11pm (10pm when in hotels or having a phone conference the next morning with people in Toronto) during the week, and 12 midnight over weekends. So, these flights mess with his sleep a lot.
All he has to do is find a job closer to home, with a minimum of travel, or keep the travel to the west coast. I have advised this ... once ... and am leaving it to him to decide, but I won't want to hear about fainting again, unless he goes to the doc, and looks for that job. I'm getting very unsympathetic the longer he leaves these undone.
Me:57 H:52 M:28 Got another lawyer last year and filed. D35,S/D twins28,D22 EA4/04 End? Who knows? "Life is like a mirror. Smile at it and it smiles back at you." — Peace Pilgrim