Quote Originally Posted by KSH
I live in Texas, and during the summer I ride in 90-100F weather.

It really is something you have to get use to. The more you do it, the better it gets. Last week, I nearly died trying to ride on a really hot day... but over the weekend I was fine. I just had to get adjusted.

It is really important that you DRINK LOTS OF WATER/SPORTS DRINK! One bottle will NOT cut it in that kind of heat. If I do a challenging 30 mile ride, I can drink through 1.5 liters in my Camelbac and 24oz in my water bottle.

I also find it good to have COOL water. Hot water is just... YUCK. How do I keep my water cool? I have a Polar water bottle. If you put ice in there, or freeze it overnight, you will have cool water for about 1-2 hours. If you have a Camelbac and put ice/water in there... it will stay cool for a good 2-3 hours.

Finally, LISTEN TO YOUR BODY. Learn what heat stroke/exhaustion is. And when you feel it happening, stop riding and take care of yourself.

Best of luck! Trust me, it gets better the more you do it!
Ditto 100%, except that I live in NC. I also ride in 90 - 105 heat pretty much all summer and you do get used to it but you need to start small. Last year, I was in good shape when I got my bike. My first ride was 105 when we left the parking lot. We did a measly 17 miles and I thought I was going to die...literally. I've never been so scared. I was shivering in 105 degree heat...it was that bad.
What I did wrong:
I tried to survive on one bottle of water (even though it was cold in my polar bottle!).
I was riding too hard...trying to keep up with the boys.
I'd never ridden in heat before.
I'd eaten horribly that day (poptarts for lunch! )

What I learned:
Electrolytes are your friend...gatorade, powerade, sportbeans...all work if taken regularly but you must find what works for you.
Water is essential. Drink it...regularly..even before you are thirsty. In that kind of heat, the thirst alarm is too late.
Nutrition is important...eat well before your ride. Protein, carbs, nutrients...not crap!
Know your limits....if it's going to be hotter than usual, take it easier. Work up to your rides in the heat.

Be prepared, be smart and good luck!