Jim and Kurt,
Maybe you missed the very first sentence:
The simplest and most important thing to ALWAYS keep in mind as a hiker is to know your limitations. You have to be brutally honest with yourself.
Y'all also didn't seem to take into account this part:
Units performing heavy activities on a sustained basis, such as a forced march or digging in,
So, if you are resting during the hottest part of the day in shade, consequently, your water intake won't need to be as high. Kidney Stones aren't the only problems. Constantly dehydrating yourself can also cause hemorrhoids, constipation, and urinary tract infections.
As far as "knowing" how much water you need, the military has spent untold millions of dollars and untold hours of interviews and research to get what information they have. I am guilty of the same exact thing. Sometimes I get more involved with what is going on around me and don't think about thirst. Here is what the "Desert Operations FM" states about "feeling":
Troops will not always drink their required amount of liquid readily and will need to be encouraged or ordered to drink more than they think is necessary as the sensation of thirst is not felt until there is a body deficit of 1 to 2 quarts of water.
Water is the key to your health and survival. Drink before you become thirsty and drink often, When you become thirsty you will be about a
“quart and a half low".
One of the keys to water intake is peeing. If your pee is darker than lemonade, or you haven't peed in a long time, you need to drink.
I don't claim to know everything, but there are some things I am an expert on. One of them is survival. The only desert area in the world I haven't had to operate in is the Gobi Desert in China. I have been to Northern and Eastern Africa, the Saudi Peninsula, Kuwait, Peru, Western Australia, and naturally, the US Southwest. A good part of my responsibility was keeping troops under me alive and in condition to work and fight. The deserts aren't the worst places in the world. Triple canopy "jungle" takes a lot more knowledge than the deserts. The desert just has water and nasty animals. Go get lost in Southern Panama or Eastern Ivory Coast (Africa). See how many ways those lovely little patches of the world can screw up your day. HAHAHA That's why one of my favorite episodes of South Park is when the kids join a group going to help save the rain forest .... until they get lost in the rain forest and have to fight off snakes, bugs, and nasty natives. The attitude changes abruptly. LOL
Enough of my ranting. I just get a little twisted when people talk about how little they need to survive. We sometimes forget that we are not the only people reading these posts. Its waaaaaaay too easy for someone to get the wrong idea Just like when some of the Treasure Magazines imply that this enormous treasure is just waiting for you to go out and pick it up. One time I can think of is in Anza-Borrego Desert. Some guy read about the treasure at San Felipe Creek (dry) and how it was easy to find. He went out there with only a bleach bottle full of water (in the Summer). Three days later, they found his car. The day after that, they found his body.
Just read through the threads on any treasure forum. You can immediately tell the people that would be dead in a day if they ever actually went out in the desert. I do it to though. I carry two 3 liter bladders in my Camelbak and a 2liter canteen of frozen water inside my ruck. I'll be climbing through the mountains for the better part of the day before I notice I have only drunk one or two liters. I don't feel bad or have any symptoms of heat stress, but that is not the information I want anybody else to take away from this.