The Institute of Medicine recommends that men get about 125 ounces of water daily and that women get 91 ounces. However, if you are exposed to lots of heat or are very active you may need to consume more.
Exercise in hot, humid conditions can dehydrate a person in as little as 30 minutes. Take caution when working out outside.
You'll need to take longer breaks, shorten the workout or intensity level, and dress appropriately.