by Michael Stump, MD, BV Orthopedics and Sports Medicine
With the nicer weather of summer, more people are taking advantage of the warmer temperatures and exercising outside. However, exercising in the heat does increase the risk of heat illness. Fortunately, precautions can be taken to safely exercise throughout the summer. Before discussing prevention, it is helpful to understand the signs and symptoms of the different types of heat illness. There is a spectrum of heat illnesses, ranging from heat cramps to heat exhaustion to heat stroke.
People with heat cramps experience muscle spasms that result from the heat, most commonly affecting the calves or thighs, but can involve any large muscle group. The cause of heat cramps is often dehydration, but can also be caused by too much hydration with just water. Heat cramps can be treated by resting and stretching the involved muscle group, as well as rehydrating.
Heat exhaustion occurs when a person sweats excessively with activity, resulting in symptoms of dehydration. Symptoms include dizziness or feeling faint, heavy sweating, cool and moist skin, and rapid pulse. If you suspect you have heat exhaustion, it is important stop all activity and rest, move to a cooler place out of the sun, and rehydrate with water or sports drinks.
Heat stroke, the most severe heat illness, occurs when the body overheats and can no longer maintain a normal temperature through sweating and other mechanisms. Signs and symptoms of heat stroke include a high body temperature, altered mental status or confusion, racing heart rate, and dry, hot, and red skin from the lack of sweat. Heat stroke is a medical emergency. If left untreated, it may result in damage to the brain, heart, kidneys or muscles. If you suspect a person may have heat stroke, seek immediate help by calling 911. While you are waiting for help to arrive, move the person into a cool environment, remove any excess clothing and attempt to cool the person. This could include putting him or her in a cold bath or wading pool and placing ice packs on the person’s head, neck, armpits and groin.
There are several actions you can take to prevent heat illness. Maintaining proper hydration throughout the day—not just while you are exercising—is important. It is recommended to drink 8-16 ounces of water 1-2 hours before exercise, 5 ounces every 10 minutes while exercising, and 18 ounces after exercise. Water is generally the best fluid to drink, but if you are exercising for more than one hour or have issues with heat cramps, sports drinks may be helpful. Take frequent breaks and rest during exercise, ideally in a cool environment. Try exercising in the morning or late evening and avoid exercising during the hottest part of the day if possible. Wear loose-fitting, light-colored clothing that absorbs sweat. Gradually increase the time and intensity of your exercise in the heat over a 1-2 week period so your body can adjust to the warmer temperatures. Finally, if you start to experience any signs or symptoms of heat illness, start treatment immediately. If symptoms do not resolve quickly, seek medical assistance.
By following these recommendations, you can safely continue your exercise routine through the summer months and enjoy the benefits of year-round fitness.