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heat stroke......worth the read!!!

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    guruguy
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    heat stroke......worth the read!!!

    Dr. Gabe Mirkin's Fitness and Health E-Zine
    May 22, 2011

    Heat Stroke

    The most likely cause of death during hot weather sports
    is heat stroke, when the body temperature rises so high that it
    cooks the brain (Medicine and Science in Sports and Exercise, July
    2008). Nobody should ever die of heat stroke because your body
    sends you warning signals as your temperature rises. Those most
    likely to suffer heat stroke are those who have arteriosclerosis,
    are overweight or are in poor shape. The treatment for a person
    who collapses from heat stroke is immediate immersion in cold
    water.
    In 1965, I almost died from heat stroke in an unimportant
    local race in Arlington, Virginia. I am still embarrassed by the
    stupidity that I showed when I ignored all of the warning signs as
    my temperature continued to climb.

    SIGNS OF IMPENDING HEAT STROKE
    First your muscles are affected, then your circulation
    and then your brain. As your temperature starts to rise, your
    muscles feel like a hot poker is pressing against them.
    It is normal for intense exercise to make your muscles
    burn, but hard exercise does not cause painful burning that feels
    like fire. Furthermore, the burning of hard exercise is relieved
    by slowing down. The muscle burning of impending heat stroke does
    not go away when you slow down.
    As your temperature rises further, the air that you
    breathe feels like it's coming from a furnace and no matter how
    rapidly and deeply you try to breathe, you can't take in enough
    air. When you exercise intensely, you can become very short of
    breath, but the air you breathe will not burn your lungs. Burning
    in your lungs, not relieved by slowing down, signals impending
    heat stroke.
    When you feel that the air is so hot that it burns your
    lungs, stop exercising. This sign means that your heart cannot
    pump enough blood from your exercising muscles to your skin, so
    heat is accumulating rapidly and your temperature is rising
    rapidly. Your temperature is now over 104 and continuing to
    exercise will raise your body temperature even further and it will
    start to cook your brain.
    Your head will start to hurt, you'll hear a ringing in
    your ears, you may feel dizzy, you may have difficulty seeing and
    then you will end up unconscious. Your temperature is now over 106
    and your brain is being cooked just as the colorless portion of
    an egg turns white when it hits the griddle.

    WHEN DOES HEAT STROKE OCCUR?
    Almost all cases of heat stroke occur when you suddenly
    increase the intensity of your exercise, such as the finishing sprint
    of a long distance running or cycling race, or an intense run down
    the field in soccer.

    HOW BODY TEMPERATURE CAN RISE UNCONTROLLABLY
    An excessive rise in body temperature is caused either by
    producing too much heat or by inability to dissipate the extra
    heat. When you exercise, almost 80 percent of the energy that is
    used to drive your muscles is lost as heat. That means that the
    harder you exercise, the more heat you produce.
    During exercise, more than 70 percent of the energy used
    to drive your muscles is lost as heat, so you heart has to pump
    extra blood from your hot muscles to your skin where you sweat.
    Sweat evaporates and cools your skin to dissipate the heat. The
    harder you exercise, the more heat your muscles produce. Everyone
    who exercises, particularly in hot weather, has to sweat to keep
    the body temperature from rising too high.

    DRUGS CAN CAUSE HEAT STROKE
    Heat stroke is more likely to be caused by inability to
    get rid of heat than by producing too much heat. Stimulants such
    as amphetamines or cocaine can kill athletes by preventing them
    from getting rid of heat by blocking sweating and blood flow to
    the skin. A single nasal dose of cocaine can block blood flow to
    the skin and sweating, to prevent a person from cooling his own
    body (Annals of Internal Medicine, June 4, 2002).

    TREATMENT
    When a person passes out from heatstroke, get medical
    help immediately. Any delay in cooling can kill him. Carry the
    victim rapidly into the shade and place him on his back with his
    head down and feet up so blood can circulate to his brain. Cool
    him by pouring on him any liquids you can find or spray him with a
    hose. It doesn't make any difference what you pour on him: milk,
    Coca Cola, beer, or anything else. Evaporation of any liquid
    cools. As you cool him, he will then wake up and talk to you and
    act like nothing has happened. While he's sitting or lying there,
    his temperature can rise again and he can go into convulsions or
    pass out again, so he must be watched for at least an hour.
    An athlete or exerciser who passes out from overheating
    should be immersed in cold water immediately to prevent brain and
    multiple organ damage. However, a heart attack can also cause a
    person to pass out and this should not be treated with cold water
    immersion. Therefore always get medical help immediately when you
    see a person pass out during exercise.

    PREVENTION
    Heat stroke is caused by continuing to exercise intensely
    in spite of all the warning signals that the body presents.
    Dehydration also increases your risk for heat stroke.
    When you compete in sports, you need to drink before you feel
    thirsty, because you slow down and lose power long before you have
    any signals to tell you that you are dehydrated. In warm weather,
    trail runners raced 12 km (7.2 miles) much faster when they took
    fluids (Journal of Athletic Training, March-April 2010). With
    fluids, they averaged 53.1 minutes compared to 55.7 minutes
    without fluids. Immediately after the race, the dehydrated runners
    had signs of greater body stress such as heart rates six beats per
    minute faster and intestinal temperatures .22 degrees C higher.

    THIRST IS A LATE SIGN OF DEHYDRATION
    You won't feel thirsty during exercise until you have
    lost between two and four pints, or two to four pounds. Thirst is
    a very late sign of dehydration. You sweat during exercise, and
    since sweat contains much less salt than your blood, you lose far
    more water than salt during exercise. As blood salt levels rise
    higher and higher, they trip off special osmoreceptors in your
    brain to tell you that you are thirsty. Since it takes a long time
    for blood salt levels to rise high enough to tell you that you are
    thirsty, you will be severely dehydrated long before you feel
    thirst.

    YOU NEED MORE SUGAR IN HOT WEATHER
    During long sports competitions, you need to take sugar
    as well as fluid because running out of sugar stored in muscles
    slows you down. The only mineral that you need to replace during
    exercise is common table salt. Water or your favorite drink plus
    food containing sugar and salt are just as effective as any sports
    drink to maintain endurance and prevent heat exhaustion. The best
    exercise drink is the one that tastes best to you, because that's
    what you will drink the most (International Journal of Sport
    Nutrition and Exercise Metabolism, January 2002).

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