Wow, to think I avoided reading this thread because I thought it was just about melting snow. I've been missing out.

Early on during a day hike I needed to "go," but wanted to wait until I found a decent place. I kept drinking water the entire time, and since the weather was very hot, I sweated alot too. I noticed that the urge to "go" didn't increase at all with all the extra water I was consuming, and I assumed it was because I was sweating it out. That's kind of interesting.