Originally Posted by
bikemig
...Nothing beats a camelbak full of ice for riding in hot weather. You can be drinking ice cold weather 3-4 hours into a ride; that's great.
I'm in Louisiana. When the humidity is really high, evaporative cooling from sweating doesn't work as it should because the sweat just doesn't evaporate as well. In my experience, your body sweats to reduce its temperature and keeps sweating even though the desired reduction in temperature ain't happenin'. I lose a lot of water as a result of the high humidity. The camelbak full of ice works fairly well for me.
Also, I use Skratch Exercise Hydration Mix when it gets hot. That seems to help.