Keeping hydrated on a hot summer day is very challenging. If you carry a drink with you, it will warm within minutes.Try these tricks of the trade. When you must run long on hot days, try to pick a route with a water fountain. Use your imagination. Remember community parks, libraries and supermarkets have them. And if you must, carry change to buy a bottle water at your local filling station or 7-11. Make several stops if needed. Stop in, get a drink, and Keep It Moving.