Daytime high temperatures average in the high 90's with humidity to match. If you are not used to this, or are not in prime condition, take it easy. More people, fighters and spectators, are lost to heat than all other types of injuries. Folks who are used to desert heat are as likely to drop as anybody else. The high humidity, which they are not used to, slows heat loss via sweating.
If the temperature and humidity get high, drink lots of water, stay in the shade, eat fruit (especially bananas)(*), and occasionally taste metabolite replacement drinks (drinks that replace minerals that the body sweats out). While Gator-Aid is not the best, it is easy to get (too high a concentration of mineral salts and too much sugar; dilute with water for best effect). If Gator-Aid does not taste bad, drink up until it does, you are in trouble. (How is that for rough and ready sports medicine?) Go easy on the alcoholic beverages. An occasional beer or wine cooler is a relief, but alcohol speeds dehydration by replacing water in the body. Your body then uses more water to metabolize the alcohol, so, in quantity, it is a very bad thing.
Other symptoms of heat disorders include flushed and dry skin, lethargy, no sweat, and, as I said, acting stupid.