I'm sorry Rip,the same thing happened to one of my former employers,he was putting a new roof on his house in the middle of august in south Florida and was'nt taking those little sips of water,anyway,a blood clot developed in his arm,when he got down he guzzled a bunch of water,when the water hit his bloodstream the clot broke loose, went into his brain and killed him.He was one of the most decent,caring,human beings I think I ever met.And yes he felt fine too,also,choronic dehydration can lead to kidney stones which are extremely painful and expensive to treat.I know this from personal experience,gunshot wounds are less painful.