Originally Posted by
cyccommute
The problem is that you don't know, usually, what half your water is. I've been on any number of tours where using half of my water to wet my body outside would have meant going without water for drinking for a significant amount of time. That's deadly in hot conditions. It's not great in cool conditions either.
The other issue is that water that goes in you will come out somewhere. If you drink too much, your kidneys will eliminate it if the sweat glands don't utilize it. You may have some problem with electrolyte loss but that's pretty easy to deal with.
Water on the outside is nice and, if you have adequate water and ready access to more, you can have a dandy wet t-shirt contest. But if you don't know where the next water source is, the wise choice is to keep it inside. Putting it on the outside doesn't keep you from dehydrating. Only drinking water will keep you from dehydrating.
You kind of missed the point. A cup of water squirted onto your skin is a cup of water that you will not have to sweat out. If it is 100+ degrees out. You will be evaporating that cup of water one way or another. If you squirt yourself with water, you are saving the water inside your body from being sweat out because you don't need to cool down as much. You are not using up extra water, or running out of water you can't afford. One way or another, that water is going to get evaporated, this way just means you don't lose salt along with it, and you don't dehydrate from sweating.