My Husband And I Had Been Driving For About 6

My husband and i had been driving for about 6 hours when he felt so dizzy and like he was going to faint that he pulled over immediately and laid his chair back. He did not faint, but slept the remaining 4 hours of the trip. I just noticed that both of his ankles are quite swollen; more than I would think normal to be caused by sitting in car for lengthy time.