Funny just recently I was leading a moderate paced hike. It was unfortunately hot out (too hot for me really - I like cold weather) but I bought along lots of water and cautioned everyone to bring water and drink it (it's amazing to me how often I have to remind people to drink!). About half way through the hike one of the women was struggled and first thing i asked is "Are you drinking?" Her reply was "I am taking small sips". I told her she had to drink up, get some real water into her before she was thirsty. She then revealed to me she was rationing her water because she didn't want to have to pee out on the trail. I reminded her better to have to pee than be airlifted to a hospital by helicopter.

Sometimes we can all be so "penny wise and pound foolish" about things. I know my body and that it doesn't do well in heat. If I have control over my schedule I ride or hike early in the day or really late and I limit the effort. It's much better for me to do a short hike/ride and limit my level of endurance to survive another day than risk heat stroke trying to get in a hard 40 miles ride.

That said, staying hydrated takes preparation - I would cut out as much caffeine as possible. I would start drinking fluids days before. I would come up with an appropiate electrolyte replacement. I know for me, I can't do salt tabs or salty food but there are products that don't bother me. And i know this sounds counterproductive, but you must eat solid during a ride/ride to stay hydrated. The water needs food in the stomach to help with absorption. Empty stomach and the water washed right through. Great to keep around and chew on - fig bars or saltines/pretzels. If one finds themselves getting dizzy or crampy then one needs to realize heat is not their friend. Time to find a gym and go indoors.

Anyway listen to that Phoenix guy if anyone knows heat it would be him!