Keep these things in mind when you exercise outside:

•Time of day. Try to avoid exercising during the hottest part of the day, 10am-3pm.
•Wear loose and light colored clothes. The light colors will help deflect the heat. Cotton material is good for evaporating sweat.
•Sunscreen-Sunscreen-Sunscreen: Protect your skin, use a high SPF.
•Stay well hydrated. Drink some water before you exercise. Carry water with you and make sure you take a drink at least every 15 minutes.

Exercise, have fun, and be safe!