Heat Illnesses: A HealthCentral Explainer

SSuchy Editor
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    A humid summer day can do more than leave you needing a shower—it actually can cause serious health problems. Here’s a rundown of some of the ways extreme heat can do your body harm and how you can protect yourself.  


    Heat Rash  

    Heat rash occurs when sweat ducts and hair follicles on the skin become blocked and irritated.  This happens because human sweat has a high salt content, which can become a potent skin irritant, especially in humid conditions. The symptoms can range from minor blisters to deep, red lumps, plus itching or a prickly feeling.

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    Heat rash usually clears up on its own after a few days, but some cases may need medical care.  The best way to prevent it is to keep your skin cool and dry, and to wash off sweat with gentle soap and water. 



    Hyperthermia, the underlying cause of most heat illnesses, occurs when the body absorbs more heat than it can dissipate. Usually, the body keeps itself cool by what’s known as thermoregulation—sweating. But when the body’s temperature regulators cannot keep up with the external temperature, you overheat. 


    The severity of hyperthermia depends on several factors, including the outdoor temperature, the health of the individual and the humidity. For example, a young, fit person will fare better on a 90-degree day in dry heat than an elderly person dealing with high humidity and high temperatures.


    Hyperthermia can lead to three heat-related illnesses: heat cramps, heat exhaustion and heat stroke. They are usually progressive so it’s important to be able to recognize the early symptoms of the milder heat illnesses, such as heat cramps. That can help you avoid a more severe condition, such as heat stroke. 


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    Heat Cramps  

    Heat cramps are involuntary muscle spasms that occur during physical exertion in hot temperatures. They usually are caused by dehydration and can feel similar to nighttime leg cramps, but last longer and can be more intense. 


    If you suspect you have heat cramps, stop whatever you are doing. Drink plenty of fluids—preferably fluids that also have electrolytes, such as sports drinks. Gently massage or stretch the muscles that are cramping and do not resume activity for several hours after the cramps subside. 


    Heat Exhaustion  

    Heat exhaustion is a condition that often follows heat cramps and precedes heat stroke. It is caused by exposure to high temperatures—usually when combined with high humidity—and strenuous physical activity.  


    Its symptoms can come on suddenly or over time depending on the individual, and can include:

    • Cool, moist skin with goose bumps
    • Heavy sweating
    • Faintness
    • Weak, rapid pulse
    • Low blood pressure
    • Muscle cramps (heat cramps)
    • Nausea
    • Headache 

    When these symptoms begin to present themselves, it’s important to respond immediately. Heat exhaustion is much easier to treat than heat stroke and usually does not result in permanent damage.


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    Stop whatever you’re doing and get to a cool, dry place. Loosen your clothing and drink cool fluids, such as water or sports drinks. Also, apply cool water to your skin. And don’t drink alcohol—it will only dehydrate you. 


    If you don’t feel better within an hour of using these treatments, seek medical attention.   


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    Heat Stroke  

    Heat stroke is the most severe of the heat illnesses. It’s caused by prolonged exposure to high temperatures and can have permanent--and even fatal--consequences if not addressed immediately.  


    By definition, heat stroke occurs when your body temperature reaches 104 degrees Fahrenheit or higher. An internal temperature that high can cause damage to your brain, heart, kidneys and muscles, and the longer your body remains at that temperature, the worse the damage will be. 


    Heat stroke’s symptoms are generally the same as those of heat exhaustion and heat cramping, but to a more extreme degree. Some victims of heat stroke will actually stop sweating, resulting in skin that’s hot and dry to the touch. 

    Heat stroke demands immediate medical attention to avoid permanent organ damage or death.  


    To keep enjoying the summer, make sure to keep an eye on the heat index before planning an all-day outdoor adventure. Always carry plenty of water and other fluids and have a plan to get out of the heat if the temperature become extreme.



    Works cited:


    National Institutes of Health. Heat Illness (2011). Retrieved from website: http://www.nlm.nih.gov/medlineplus/heatillness.html


    Mayo Clinic (2012), Heat Cramps: First aid (2011). Retrieved from website: http://www.mayoclinic.com/health/first-aid-heat-cramps/FA00021


    Mayo Clinic (2011), Heat Exhaustion.  Retrieved from website: http://www.mayoclinic.com/health/heat-exhaustion/DS01046


    Mayo Clinic (2011),  Heat Stroke.  Retrieved from website: http://www.mayoclinic.com/health/heat-stroke/DS01025


    Mayo Clinic (2012), Heat Rash. Retrieved from website: http://www.mayoclinic.com/health/heat-rash/DS01058

Published On: June 22, 2012

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