I used to get sick during my flight training. The Texas summers get hot, bumpy, and muggy. I even got nausous once in a while when I was instructing. You get over it, or learn how to deal with it. I suggest you take early morning or late afternoon flights, don't eat before, chew a pepto before the flight, wear one of those air sickness watches, and keep the window open as much as possible. The bigger the plane, the easier it is. And no, to all those who mis-read this, I don't get sick anymore. lol