When summer arrives, many people are eager to take their workout outdoors and embrace the warm temperatures and sunny days. While most know not to overexert themselves during hot spells and to stay inside on days when the temperatures are particularly high, it doesn’t take much to feel the effects of summer heat. Performing simple everyday activities in the extreme heat like gardening or going for a walk can prompt heat illness just as easily as more strenuous activities.

“One of the misconceptions about heat illness is that you need to run a marathon to feel the effects of the heat, but that isn’t the case,” says Dr. Irving M. Herling, cardiologist at Lankenau Medical Center. “Heat illness can happen to anyone at any fitness level during any activity.”

Recognizing the symptoms of heat illness and knowing how to respond to them can help save a life. The Centers for Disease Control and Prevention identifies two types of heat illness: heat exhaustion and its more severe partner, heat stroke.

Heat Exhaustion
Heat exhaustion is a milder, more common heat-related illness that develops after several days of exposure to high temperatures and a loss of water through sweat. Vacations, camps and sports practices can all prompt heat exhaustion, so keep an eye out for symptoms such as:

• Heavy sweating
• Muscle cramps
• Weakness
• Dizziness or headaches
• Fainting

To prevent heat exhaustion, be sure to drink plenty of water. If you’re practicing as part of a sports team or doing something that requires a great deal of physical activity, bring multiple water bottles along, and make sure to refuel afterwards with a sports drink, which contains electrolytes. In addition, be sure to take plenty of breaks, preferably in air conditioning.

Heat Stroke
This more severe heat illness occurs when the body is unable to regulate its temperature. Temperatures can rise to 106 degrees Fahrenheit or higher within ten to 15 minutes, and can cause death or permanent disability if it is not treated immediately. Symptoms of heat stroke include:

• Extremely hot, high body temperatures
• Red, hot and dry skin, but no sweat
• Rapid pulse
• Throbbing headache and dizziness
• Nausea
• Confusion

Because heat stroke is a more serious condition, immediate medical attention is required. If someone is exhibiting signs of heat stroke, call for help and, in the meantime, bring them to a shaded area and cool them off by immersing them in cool water. However, it is important not to give any fluid to someone suffering from heat stroke, so hold off on having them drink water.

To decrease your likelihood of being affected by heat exhaustion or stroke, try to limit outdoor activity to the early morning and evening hours, which are cooler parts of the day. Wear light, loose-fitting clothing, as well.

Although these heat illnesses can affect anyone, even the most frequent gym-goers, certain groups are more at risk than others, especially those with a heart condition.

“The high heat and humidity of summer are uncomfortable for most of us, but for anyone with a heart condition, it goes beyond being uncomfortable. A heart condition can make it more difficult to pump blood to the heart and regulate blood pressure, which can have dangerous, and potentially deadly, results,” explains Dr. Herling.

For anyone with a heart condition, this increased risk does not mean that you need to avoid the outdoors altogether, but it does mean you should be especially aware of the symptoms of heat illness and take extra precautions on especially warm days. If you take a medication for heart disease, such as diuretics, water pills or beta-blockers, talk to your doctor before exploring outdoor activity, as they can make extreme temperatures even more dangerous.

If you have questions about your heart health or recommended level of activity in the summer heat, talk to your doctor. A Main Line Health cardiologist can help you determine how much time outside is healthy for you based on your medical history.