It's important to remember to keep drinking even after you get off the bike. Several years ago I was part of a group riding across the US and before we crossed the Mojave Desert we were constantly told by the organizers to drink, drink, drink. Every one made it through the desert without any trouble, but that night at dinner several people started to get sick and and ambulance was called. A couple of the riders were taken to a local hospital and put on intravenous fluids and were fine the next day. It turns out that once they got to the motel after crossing the desert they stopped drinking and the doctors said they should have kept drinking as much as possible even when they were in an airconditioned motel room.
The person I felt sorry for was the restaurant manager who had to try to convince his other customers that all the people getting sick and taken away by the ambulance weren't that way as a result of his food.