Drink plenty of water—a cup (8 ounces) of water every hour during non-strenuous activity or a cup every 15 to 20 minutes during strenuous activity—especially on hot days.
Our bodies produce a tremendous amount of heat and sweating is an important mechanism to keep us cool. Frequent hydration helps us to avoid dehydration and bolsters our ability to sweat and radiate heat through our skin, keeping our body temperature from reaching dangerously high levels.