I have been following the Tour of California for the first two stages and I felt compelled to write a quick article on how to ride well in hot weather. A lot of these euro riders are coming over from one of the coldest and wettest springs they have ever had and this heat is a true shock to the system. As for the domestic based riders they have already raced in the hotter weather with Tour of the Gila just a week before the Tour of California.
Heat acclimation is usually important for most athletes racers and non racers alike, so if you can get in some warm/hot weather riding before your goal event or ride.
Hydration is the most important factor in hot weather riding. You must drink at least one bottle every 25-45 minutes (if not more on really hot days) and this bottle should have some sort of electrolyte replacement in it. Some examples of drinks that work are Cytomax, Endurox, Gatorate, Clif and even Pedialyte. All of these are something that I have used and they will make your ride in the heat much more enjoyable. If you are not replacing what you are sweating out you will eventually cramp in a bad way. If you know you will be riding in hot weather the day before your ride get in a meal with a higher sodium content the night before and drink tons of fluids that evening. The sodium content will allow your body to retain more fluids and you will stay more hydrated throughout your ride.
One other trick is to dump cool or cold water on your body every chance you get. This helps keep your core temperature down and you will definitely run the engine at a cooler temperature without overheating it. Keeping your head wet and dousing your clothing in cold water will make a world of difference on a really hot day. Actually in the Tour of California the riders that were in the break away most likely had a tough ride because of the breakaway they were in but they had it easy because they were able to get so many bottles to stay well hydrated and also dump over their bodies to keep the core cool. Those guys were usually finishing the day better off than the riders in the peloton who got much fewer bottles.
Last but not least make sure to wear light colored clothing and make sure that it breathes well. If you have clothing that is a bit thicker or is not good at wicking away moisture you will be at a big disadvantage. There are some great companies out there that make amazing summer clothing like, Nalini, Pactimo, Assos, Castelli, Capo, Pearl Izumi and many more.