How Can You Prevent Exertional Heat Related Illnesses? 

The North American Society for Pediatric Exercise Medicine and the National Athletic Trainers’ Association developed an Inter-Association Task Force on Exertional Heat Illnesses position statement. Some recommendations on how to prevent exertional heat related illness include: 
 

• When exercising in high heat and humidity, rest 10 minutes for every hour and change wet clothing frequently.
• Avoid the midday sun by exercising before 10 a.m. or after 6 p.m., if possible.
• Use a sunscreen with a rating of SPF-15 or lower dependent upon skin type. Ratings above SPF-15 can interfere with the skin’s thermal regulation.
• Wear light-weight and breathable clothing.
• Weigh yourself pre and post exercise. If there is a less than a 2 percent weight loss after exercise, you are considered mildly dehydrated. With a 2 percent and greater weight loss, you are considered dehydrated.
• During hot weather training, dehydration occurs more frequently and has more severe consequences. Drink early and at regular intervals according to the American College of Sports Medicine. The perception of thirst is a poor index of the magnitude of fluid deficit. Monitoring your weight loss and ingesting chilled volumes of fluid during exercise at a rate equal to that lost from sweating is a better method to preventing dehydration.
• Rapid fluid replacement is not recommended for rehydration. Rapid replacement of fluid stimulates increased urine production, which reduces the body water retention.
• Individuals involved in a short bout of exercise are generally fine with water fluid replacement of an extra 8-16 ounces. A sports drink (with salt and potassium) is suggested for exercise lasting longer than an hour, such as a marathon, and at a rate of about 16 to 24 ounces an hour depending upon the amount you sweat and the heat index.
• Replace fluids after long bouts of exercise (greater than an hour) at a rate of 16 ounces of fluid per pound of body weight lost during exercise.
• Avoid caffeinated, protein, and alcoholic drinks, e.g., colored soda, coffee, tea.
• Acclimate to exercising outdoors, altitude, and physical condition. General rule of thumb is 10-14 days for adults and 14-21 days for children (prepubescent) and older adults (> 60 years). Children and older adults are less heat tolerant and have a less effective thermoregulatory system.
• Educate and prepare yourself for outdoor activities. Many Web sites offer heat index calculations for your local weather conditions. 

Summer weather does not have to sideline your outdoor exercise regimen. The above suggestions can help you plan and find ways to modify your routine to exercise safely in warm, hot, and humid weather.