Last year we had a trip to WDW (Deluxe Magic, Poly, Cindy's, the works!). Buzz had been acting "down", finally I took him to the doctor through a snowstorm the day before we left. He had an ear/sinus infection--great! We jsut brought the meds with us (they kept them cold until our room was ready--miraculously, our room had a fridge, although we didn't ask for one, pay for one, or the rooms of our other family members didn't!) We just really took it easy the first couple days. Buzz slept in my arms on the flight down. I was in the last row on the plane--real uncomfortable, couldn't move, couldn't do anything, but I was so glad he was getting the rest he needed, I would have done it all week! By our second day at WDW, he was his old self, although we were careful about his schedule, not getting him run down. I would recommend you do a quick info check as you check in--tell them your child is under the weather, find out what to do if your child gets worse, etc. Also, if you go to parks, locate the first aid on the map first thing. Not to sound paranoid, but looking into these things will give you some peace of mind. Beyond that, I would just echo the people who said plenty of rest, fluids, etc.