What if you get thirsty in the tour de france?

Answer 1

Then you drink.

Riders will have a bottle, or maybe even two in bottle holder(s) on the frame. Usually on the down tube. Unless the riding is really intense, it's fairly easy to reach down. grab the bottle and have a sip.

When the bottle goes empty, a good rider can request one of the support riders to drop back through the pack to the support car and pick up another bottle for him. Support riders, domestiques, will have to fetch their own.