Not to mention; trapped in an attic, with no water in August temperatures.
It's unthinkable.
I was wondering about the temps there: thinking that, too. I saw on wlox's website: current 34 F, feels like 13F!!
Horrible!
I'm confident they can find water if they are desperate enough. Perhaps not very good water, but given the choice of death from dehydration and drinking the flood waters the latter is preferable. So long as they aren't too salty they'll maintain life and the water born infections they may carry can be treated if you stay alive long enough to permit rescue.