In my last blog, ”The Heat is On!”, I discussed acclimating your body to exercising in hot weather. While most people can safely do this, I always recommend talking to your healthcare provider if you have any medical conditions that may make it inadvisable for you. Even well-conditioned athletes may overdo it from time to time, and it’s certainly true for those who are not well-conditioned. So, rather than write my own blog about what can go wrong, I turned to mayoclinic.org for the following information about heat-related illness. As an Arizonan who likes to run, I found this to be very helpful.
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.
The result may be a heat-related illness. Heat-related illnesses occur along a spectrum, starting out mild but worsening if left untreated. Heat illnesses include:
- Heat cramps. Heat cramps, sometimes called exercise-associated muscle cramps, are painful muscle contractions that can occur with exercise. Affected muscles may feel firm to the touch. You may feel muscle pain or spasms. Your body temperature may be normal.
- Heat syncope and exercise-associated collapse Heat syncope is a feeling of lightheadedness or fainting caused by high temperatures, often occurring after standing for a long period of time, or standing quickly after sitting for a long period of time. Exercise-associated collapse is feeling lightheaded or fainting immediately after exercising, and it can occur especially if you immediately stop running and stand after a race or a long run.
- Heat exhaustion. With heat exhaustion, your body temperature rises as high as 104 F (40 C), and you may experience nausea, vomiting, weakness, headache, fainting, sweating and cold, clammy skin. If left untreated, heat exhaustion can lead to heatstroke.
- Heatstroke. Heatstroke is a life-threatening emergency condition that occurs when your body temperature is greater than 104 F (40 C). Your skin may be dry from lack of sweat, or it may be moist.
You may develop confusion, irritability, headache, heart rhythm problems, dizziness, fainting, nausea, vomiting, visual problems and fatigue. You need immediate medical attention to prevent brain damage, organ failure or even death.
Pay attention to warning signs
During hot-weather exercise, watch for signs and symptoms of heat-related illness. If you ignore these symptoms, your condition can worsen, resulting in a medical emergency. Signs and symptoms may include:
- Muscle cramps
- Nausea or vomiting
- Weakness
- Fatigue
- Headache
- Excessive sweating
- Dizziness or lightheadedness
- Confusion
- Irritability
- Low blood pressure
- Increased heart rate
- Visual problems
If you develop any of these symptoms, you must lower your body temperature and get hydrated right away. Stop exercising immediately and get out of the heat. If possible, have someone stay with you who can help monitor your condition.
Measuring core body temperature with a rectal thermometer is essential to accurately determine the degree of heat injury. An oral, ear or forehead thermometer doesn’t provide an accurate temperature reading for this purpose. In cases of heatstroke, due to confusion and mental status changes, you won’t be able to treat yourself and you’ll require emergency medical care. The most effective way of rapid cooling is immersion of your body in a cold- or ice-water tub.
In cases of heat exhaustion, remove extra clothing or sports equipment. Make sure you are around people who can help you and assist in your care. If possible, fan your body or wet down your body with cool water.
You may place cool, wet towels or ice packs on your neck, forehead and under your arms, spray yourself with water from a hose or shower, or sit in a tub filled with cold water. Drink fluids such as water or a sports drink. If you don’t feel better within about 20 minutes, seek emergency medical care.
When to see a doctor
If you have signs of heatstroke, you’ll need immediate medical help. If your core temperature is less than 104 F (40 C), but it doesn’t come down quickly, you’ll also need urgent medical attention. In some cases, you may need fluids through intravenous (IV) tubes if you’re not able to drink fluids, or not able to drink enough fluids.
Get cleared by your doctor before you return to exercise if you’ve had heatstroke. Your doctor will likely recommend that you wait to return to exercise or sports until you’re not experiencing symptoms. If you’ve had a heatstroke, you may require many weeks before you are able to exercise at a high level. Once your doctor clears you for exercise, you may begin to exercise for short periods of time and gradually exercise for longer periods as you adjust to the heat.