My husband, who is 76 & in relative good health, started a headache this morning while cleaning out our car for an auto trade. Tylenol stopped it. On the way to the car dealer, however, he experienced some confusion. Then while in the new car getting instructions on how to use all of the various components, he felt dizzy. By the time we got home, his headache had returned & he felt nauseated. Took a Tylenol & has been in bed in the dark for 2 1/2 hours. Had a dry heave. He says he just needs to rest & sleep it off. He very well could be dehydrated and hasn't eaten much today. There is stress/anxiety connected to the new car purchase as well. Should I take his word and leave him alone or should I be concerned.