Exercising in hot weather puts extra stress on your body. Both the exercise and the outside temperature increase your core body temperature. To help cool itself, your body sends more blood to circulate through your skin. This leaves less blood for your muscles, which then increases your heart rate. If the humidity is high, your body has additional stress because sweat doesn’t readily evaporate from your skin. That pushes your body temperature even higher.
Under normal conditions, your skin, blood vessels and perspiration level adjust to the heat. But these natural cooling systems may fail if you’re exposed to high temperatures and humidity for too long, you sweat heavily and you don’t drink enough fluids. Heat illnesses include:
- Heat cramps. Heat cramps are painful muscle contractions, mainly affecting the calves, quadriceps (front of your thighs) and abdominals. Affected muscles may feel firm to the touch. Your body temperature may be normal.
- Heat exhaustion. With heat exhaustion, your body temperature rises as high as 104 F, and you may experience nausea, vomiting, headache, fainting, weakness and cold, clammy skin. If left untreated, this can lead to heatstroke.
- Heatstroke. Heatstroke is a life-threatening emergency condition that occurs when your body temperature is greater than 104 F. Your skin may be hot, but your body may stop sweating to help cool itself. You may develop confusion and irritability. You need immediate medical attention to prevent brain damage, organ failure or even death.
During hot-weather exercise, watch for signs and symptoms of heat-related illness.
- Muscle cramps
- Nausea or vomiting
How to avoid heat-related illnesses
- Watch the temperature. Pay attention to weather forecasts and heat alerts
- Get acclimated. If you’re used to exercising indoors or in cooler weather, take it easy at first when you exercise in the heat. As your body adapts to the heat over the course of one to two weeks, gradually increase the length and intensity of your workouts.
- Know your fitness level. If you’re unfit or new to exercise, be extra cautious when working out in the heat. Your body may have a lower tolerance to the heat. Reduce your exercise intensity and take frequent breaks.
- Drink plenty of fluids. Dehydration is a key factor in heat illness. Help your body sweat and cool down by staying well hydrated with water. Don’t wait until you’re thirsty. If you plan to exercise intensely or for longer than one hour, consider a sports drink instead of water.
- Dress appropriately. Lightweight, loose fitting clothing helps sweat evaporate and keeps you cooler. Avoid dark colors, which can absorb heat. If possible, wear a light-colored, wide-brimmed hat.
- Avoid midday sun. Exercise in the morning or evening, when it’s likely to be cooler outdoors. If possible, exercise in shady areas — or do a water workout in a pool.
- Wear sunscreen. Sunburn decreases your body’s ability to cool itself.
- Have a backup plan. If you’re concerned about the heat or humidity, stay indoors. Work out at the gym, walk laps inside the mall or climb stairs inside an air-conditioned building.
- Understand your medical risks. Certain medical conditions or medications can increase your risk of a heat related illness. If you plan to exercise in the heat, talk to your doctor about precautions.
By: Janet Hunt