Summer Outdoor Exercise: Heat Illnesses

It is fun to get outside and be active in the summer. Playing some driveway basketball or going for a run is good for your body and your heart. There are several benefits to outdoor exercise: fresh air, vitamin D from the sun and the calming effect of nature. However, there are some dangers to exercising and physical activity in the heat.

Your body cools itself by sweating. When sweat evaporates it regulates your body temperature. Hot weather combined with exercise or physical exertion makes it harder for your body to cool itself.

There are 4 factors that go into determining how much heat stress there is: Air Temperature; Humidity (the amount of moisture in the air); Wind Velocity (breeziness) and Thermal Radiation (how sunny it is).

Exercising outdoors on a cloudy 80 degree day with a 15mph wind has less heat stress on your body than exercising on a sunny 80 degree day with no wind.

Humidity impairs your body’s ability to sweat and cool itself. Therefore, a 90 degree day with 95% humidity is riskier for heat related illness than a 90 degree with 40% humidity.

Heat Cramps –

Heat cramps are the mildest form of heat illness.

Symptoms of heat cramps include: heavy sweating, fatigue, thirst and painful muscle cramps. Muscle cramps usually occur in the arms, legs or stomach but can be any muscles in the body.

To treat heat cramp you should hydrate with water or sports drinks, get in the shade or air conditioning and rest. When you sweat you lose fluids, salts and minerals. Sports drinks contain electrolytes that are important in maintaining good health. Many sports drinks contain sugars and calories, so read labels and find a sport drink brand that works for you and your health goals.

Treating heat cramps promptly helps stop you from progressing to heat exhaustion.

Heat Exhaustion –

Heat exhaustion is a more severe illness than heat cramps. If you don’t stop your heat cramps you can quickly progress to heat exhaustion.

Signs of heat exhaustion include: dizziness, fainting, vomiting, cold clammy skin, hot dry skin, irregular pulse (weak or rapid), headache, goose bump when in the heat.

If your symptoms do not improve in 1 hour contact your doctor.

Heatstroke –

Heatstroke is the most severe heat illness. Heatstroke requires immediate medical attention. Heatstroke can cause permanent damage to your brain and organs. It can lead to death.

Signs of heatstroke include: mental confusion, no sweating, muscle twitching, headache, shallow breathing, rapid pulse, no sweat, hot dry skin, dizziness, unconsciousness, coma, body temperature 102 degrees to 104 degrees.

To treat heatstroke contact emergency medical professionals and try and cool the person as rapidly as possible. A bath of cold water is a good solution or apply ice and cool water.

Here is a helpful infographic from the CDC:

Heat Illness Prevention –

There are some things you can do help your body stay healthy and safe when outside exercising in the heat.

Exercise in the early morning or late afternoon. Stay away from physical activity and exercise in the hottest parts of the day.

Stay hydrated. Drinking water or sports drinks with electrolytes can help keep you from dehydration. Staying hydrated allows your body to sweat and maintain a healthy body temperature.

Dress appropriately. Wear lightweight loose clothing and as little clothing as possible so heat can escape.

Know the weather conditions. You need to check the 4 weather factors that can impact heat stress: temperature, humidity, wind velocity and whether it is sunny or cloudy.

Seek a cool environment. If you start to feel overheated, cramping muscles, dizziness, feel faint or nauseous stop what you are doing and get to a shady or airconditioned spot.

Most heat illnesses happen when you are too active in the heat or too long in the heat. Those who are older, sick, overweight or very young are the most vulnerable. Make sure to assess the conditions of the day and plan your physical activity accordingly.