. >> scott hallenbeck is executive director of usa football. it's an organization that oversees youth football leagues. >> we make sure we teach players, coaches and parents about the symptoms and signs of heat stroke in our coaching schools, in our online courses. a number of resources to help them understand that it is critical to young athletes. >> coach dan bevilacqua took the usa football course. he knows higher temperatures mean extra safety measures are necessary. >> so we tell kids when the heat index is above 90, we don't wear equipment at all, we do mostly agility drills, and we don't do any contact. >> and they break more frequently for getting water. hydration is a key part of prevention. and it begins well before the whistle blows for practice. [ whistle ] >> we tell them even before the season starts when we address the parents, they should drink at least one liter of water three hours before practice time. >> you've heard the expression, an ounce of prevention is worth a pound of cure. in this case, it's a bottle of prevention, a