Yup. Put your hair up in a bun high up on your head as you can get it. Or if it's still in between your shoulders and your ears then make several lumpy little half-through pony tails. Like, take a rubber band or small scrunchie and act like you're making a simple ponytail. But instead of pulling the hair all the way through only pull it halfway through. This works especially well if your hair isn't long enough to twist around in a bun. do that all over your head and you're good to go.
Your just going to have to suck it up that you have to wash your hair in the morning or in the early afternoon/
Don't use a blowdrier on your dreads, either, unless you're on bedrest or it's an absolute emergency. You'll kill your hair.