Loose-fitting polyester/cotton blend clothing or other fabrics designed to wick away moisture will help keep your body cooler. It's not sweating itself that cools your body, but rather the evaporation of sweat. So avoid wearing clothing that soaks up sweat but doesn't allow it to evaporate.
The more you sweat, the more you'll need to rehydrate to avoid heat cramps, exhaustion, or worse, heat stroke. Make sure to carry a bottle of water with you, and drink often. You're better off drinking a small amount more frequently than downing a lot of water all at once.
Avoid sports drinks and other sugary beverages though, as these will do you more harm than good. For those of you who are exercising to lose weight, you should also know that sports drinks are usually anything but low calorie. There is a perverse irony of people who are working hard exercising to burn off calories, only to be slurping down more calories and HFCS, which is linked to obesity, while they're working out.
If you exercise for 30 minutes a day, at a moderate intensity, water is the best thing to help you stay hydrated. It's only when you've been exercising for longer periods, such as 60 minutes or more, or at an extreme intensity, or on a very hot day or at your full exertion level, that you may need something more than water to replenish your body.
As stated in the featured article, sun, humidity and pollution levels are most intense during the midday, so to minimize the effects of the heat, work out either first thing in the morning, or in the late evening.
While the featured article dispenses the conventional advice to apply sunscreen before heading outdoors, I strongly disagree with this recommendation. Not only are you forfeiting the benefits of vitamin D production in your skin, you're likely slathering on toxic and hormone-disrupting chemicals that will transfer directly into your blood stream.Instead, I take a daily astaxanthin supplement, which acts as an internal sunscreen and skin protector. Many athletes complain of feeling ill from overexposure to the sun after long training sessions outside. However, many report astaxanthin has allowed them to stay in the sun for longer periods of time, without feeling ill and without burning. Besides copious testimonials and anecdotal evidence, scientific studies have substantiated these skin protective effects. If you decide to give astaxanthin a try, I recommend starting with at least 2 mg per day. I have been taking 8 mg per day for the past couple of years and I can't remember the last time I was sunburned. Another common-sense strategy to protect your skin is to wear a light-colored, loose-fitting, long-sleeved shirt and a cap.
Start slow, exercising in the heat for just a few minutes at a time, and gradually increase the amount of time as your tolerance builds. Again, signs of increased tolerance include breaking into a sweat more rapidly, and your sweat being more diluted or watery.
Exercising in shady areas, such as tree-lined trails and parks, will help you stay cooler when the temperature rises.
Any kind of water exercise is an ideal choice on a hot day as water naturally cools your body. While most city- and suburb-dwellers may opt for a pool, your best alternative would be swimming in a lake, ocean, or other natural body of water, to avoid hazardous pool chemicals. An added boon of that is that you'll naturally ground yourself, as long as you're barefoot.
Surprising as it may sound, emerging research suggests modern running shoes, with their heavily cushioned, elevated heels, may actually encourage runners to strike the ground with their heel first—a move that generates a greater collision force with the ground, leading to an increased potential for injury. Fore-foot- and mid-foot-strike gaits were probably more common when humans ran barefoot or in minimal shoes, and may actually protect your feet and lower limbs from some of the impact-related injuries now experienced by a high percentage of runners.
Running cold water over your forearms will help reduce your body temperature. Many public areas have drinking fountains or public rest rooms where you can do this. Using a spray bottle, spray cool water on your skin while fanning air on it—either with a small portable fan, a paper fan, or even a towel or piece of clothing. As the water evaporates, your body temperature will drop.
Symptoms of heat exhaustion can come on quickly if you're not paying attention, and since fainting is one of the symptoms, it can be far safer to exercise with a partner when the heat is on. (Other warning signs and heat-related symptoms will be reviewed below.)