The heat is a major factor down in the dirty south (Hotlanta, GA). When it's really hot we ride at night, I have to get the hours in and have a good set of lights so riding into the night works for me. I did a World cup MTB in Conyers, GA (Olympic course) that was so hot and humid that the 2nd place finisher was airlifted out due to heat stroke. That's why he is not on his respective block, he was from Ohio and not used to the hardcore weather down here. I managed to get forth. I could have done better but I only had one working eye at the time because the other one had 10 stitches around it and swollen shut from hitting a tree the night before... Lost some of my ear too! The E-room doctor told me I was not going to be able to race because the eye would be useless but I figured I knew the trail pretty well and it was mostly single track so I was good to go!
If cramping is an issue then I would suggest picking up a bottle of Hammer Nutrition’s Endurolytes. They have worked for me when the cramps started setting in on a long, hot & hard century. They are also great for Ironman’s. Of course drink plenty of water and add some sports drinks into the mix as well ( I like HEED and Accelerade).
Ride-on,
-Scott