Here in Alabama "summer time" usually means temperatures in the 90s (at least) and in addition a lot of humidity. Even if you do not live in the deep south, chances are you'll be exhausting outside your home. That does not mean that you have to give up your outdoor training. Try these cool tips from Michele Olson, a professor of motion science at Auburn University in Montgomery, Ala. 
- Drink up. Mix 8 ounces of water at least 30 minutes before you start, then add another 4 ounces every 1
- Follow the 3 L. When it comes to clothing, you should sit light, light and loose. And leave the cotton at home (unless you like to wear a thick, wet cloth). Instead, you should be made with technical fabrics like Coolmax and Dri-Fit – they drain sweat to keep you cooler.
- Protect yourself. Your skin needs time to soak up sunscreen. Therefore, use it at least 30 minutes before training. (Cloudy? Wrap it up anyway – harmful UV rays can still penetrate.) And do not forget your hat and sunglasses.
- Go to the trees. The path is shady and sunny.
- ease. When it's very hot, you need to cut your body a bit loose. Keep the intensity at moderate intensity (avoid the treadmill sprints), trim the workout time by about 10 minutes, and exercise in the morning (before the earth has picked up the heat of the day). Try one of those countless beads of sweat as you dribble over your face. Super salty? You're probably losing too much water and sodium – and that can lead to cramping or dehydration. Go back to Pronto. The same applies if you feel bad or weak during exercise or are dizzy.
- Think of a gym . If both heat and humidity are higher than you're used to – especially if you're planning an afternoon workout – then you'll need to pick the treadmill (or a great DVD) over the pavement. Here's the reason: The evaporation of your sweat keeps you from overheating. In pea-soup-like conditions this can not happen. So bite the ball, hop on the sidewalk and remember, because there is always tomorrow.