Straw, as mentioned in an earlier post, is a good idea. If it's real wet put down a piece of board and throw the straw on it
They should be fine, but you don't want them being soaking wet 24/7. Main thing if they are soaking wet and cold is to look for labored breathing, purple comb, etc or other signs their heart is giving out. I doubt that it is going to be cold enough this time of year to give you any problems.
Don't worry, give them a once over and if they look OK then they most likely are OK.