Our bodies have an amazing built-in air conditioning system - it's called sweating. As sweat evaporates from the skin, it cools the entire body. Also, as blood circulates between muscles and the skin, it helps dissipate heat and keeps the body's core temperature relatively constant. But summer heat and humidity can overpower these natural cooling systems, causing heat related illnesses and heatstroke.

Allow your body to adjust to higher temperatures. Shorten the length and intensity of your workouts,
and then gradually build up your effort.

Exercise in the morning or in the evening, when the temperature is coolest. Stay indoors between 10 a.m. and 4 p.m. Wear light-colored, loose, permeable clothing. Avoid cotton, which doesn't allow sweat to evaporate; choose polypropylene fabrics that absorb moisture from the skin instead.

Keep yourself hydrated with water or sports drinks. Drink before and after exercising and carry a bottle of water with you. Also, drink before you feel thirsty.

Exercise indoors: Walk in the mall, join a gym or find a fun exercise tape. If you feel overheated, nauseous, weak or dizzy, stop exercising immediately, get to a cool place and start drinking fluids. Follow these guidelines if you stop
sweating or if your muscles start to cramp. Protect your skin with sunscreen with at least SPF 15, sunglasses and a hat with a wide brim.