How Hot is it?

My CamelBak holds 100 oz. I drank two of them today.  That's 12.5 lbs. of water.  My weight is the same as when I got up this morning.  I wonder how much salt it takes to push 12.5 lbs. of sweat in a 6 hour period.  Dunno but I'm gonna go suck on some rock salt till it doesn't taste good any more.