Most important of all aspects of heat is hydration. When hydrating for a run, the previous days are just as crucial as the day itself. Prepare for your runs ahead of time by drinking plenty of water. While it is recommended to consume 8 cups of water a day, on hot days, runners will need to consume more than that. During a run, either carry water or make sure you run near areas that you can access water in an emergency- parks, convenience stores, restaurants, etc. Make sure you keep the electrolytes up also!