bsdc said:
I'm getting up early, filling my camelback with ice water
Bad idea right there. Don't fill up your camelback with ice, the cold water shocks the hell out of your body and you end up feeling pretty sick and drained a lot earlier than you would if the water temp was a little more normal. Being acclimated, prepared and going out for a reasonable ride is what needs to happen. First of all, some parts of Texas are about as much "year round riding" as some parts of Arizona, so you will have to curtail your activities to some extent. Your body will simply go through more water than you can possibly carry, and you'd also need the electrolytes to do anything with a whole lot more water. That means you'll have to scale back a bit.
We just did a reasonable ride this am, but it wasn't very early so we were riding in 90 degree or more heat most of the time (this in Arizona).
What made it possible for me was a good base of food before hand, must have the glucose in the system and the carbo reserves to ride, otherwise you could end up in a world of hurt. Food for breakfast was a bagel, 3 slices of bread and a bananna (potasium). I tried to drink a lot of water before hand, I have a 100oz camelback, and I took additional water with me. If you're not using this much water or more, that's probably your number one problem. In the real heat 100oz in an hour or so is a reality, and you can probably stretch to two hours with that and some extra water, but a dinky 70oz camelback or a waterbottle isn't going to cut it. So drinking lots of water and staying hydrated is just oh-so-important. A lot of people don't want to go through the "trouble" of actually doing this though. Also make sure during the ride you are eating about every 45 minutes, otherwise you're glucose will drop down and you'll bonk. Obviously it takes a lot of water to digest food and keep your body cool, so ride in a place where you can get water if necessary.
I use a loose-fitting sleveless jersey that is a pretty light mesh, it breathes much better than most "cycling" jerseys that I see, so that helps me a bit.
Not sure what else you can do, I know how hot and nasty it stays in texas at night and even in the morning lots of times. I try to do evening rides here when it's really hot, and the nice thing is that it's usually getting better the entire time while you are riding and the sun is getting lower, but I don't think the temperature will drop as much as it does here. Even though I don't really consider it to every be "too hot" to ride where I'm at (because I don't live in phoenix), I still go up to higher elevation a good deal, as well as our local trails go up pretty nicely too. That kind of allows many of us that live in mountainous areas an "escape", so that's where we get a lot of summer riding as well.
