I have never seen any of my hard working friends drinking water. And they aren't exactly dying. And I mean "working". You never even saw a farmer on a 9n tractor for hours in the hot sun drinking water. Sure, if you are sweating buckets, I'm sure there is the "eventual" requirement to replenish your fluids. These people who aren't even sweating carrying around water, give me a break!
I had a roof put on a while ago, of course it had to be on the hottest days of the year. Those two guys didn't drink water either! Maybe they had a drink at lunch. I'm guessing, they are still both alive.