June 4, 2010

Tips to Stay Cool: Avoiding Heat Exhaustion

Posted in Uncategorized at 10:16 PM by lanaholt

By Steve Edwards

As summer nears, the lure of sunshine, warmth, and poolside idleness becomes tempting. This is especially true if you’ve just spent the spring working on looking good in your bathing suit. But, keeping your toned physique through the summer months involves another challenge. As the temperatures soar, heat exhaustion becomes more a likelihood than a concern. Let’s take a look at how to stay cool so you can ramp up your workouts, whether it’s P90X® or Power 90®, even as the mercury rises.

What is heat exhaustion?

Heat exhaustion is one phase of hyperthermia, a condition that occurs when the body produces or absorbs more heat than it can dissipate. In its advanced state, heat stroke, medical attention is absolutely necessary because of the threat of death. Minor cases aren’t life threatening and occur regularly, especially in warm weather, but should be treated seriously because heat exhaustion can quickly turn into heat stroke if allowed to progress.

The weather needn’t be hot for hyperthermia to occur. Heat can be created artificially by drugs or medical devices or naturally through exercise or improper fueling of the body. But as the weather gets warm, your margin for error decreases, because your body temperature will increase without you doing anything active. This is especially true early in the year when you aren’t used to the warm weather. Those coming off of a cold winter are particularly vulnerable.

By the numbers, it looks like this: Normal body temperature is around 97° to 98°F (36° to 37°C). Anything above 104°F is considered life threatening. At 106°F, brain death begins, and by 113°F, death is nearly certain. Since anytime you “feel hot” your body temperature is edging its way over normal, it’s not hard to see that you don’t have a large buffer before your condition may become serious.

Signs and symptoms of heat exhaustion

Sweating is your body’s response to overheating. The process pulls heat from inside the body and pushes it out, where it will evaporate on the skin and cool the body further. So sweating is the first sign of overheating and should indicate that proper hydration strategies be adhered to in order to keep this process working.

When you’re hot and stop sweating, your body is in serious trouble and aggressive measures (see daily strategies below) should be initiated. Prior to this, you would likely experience other warning signs. The most basic is feeling hot. This means that your sweating mechanism is being overworked or is not doing its job properly. The skin will then become red or flush. Headaches, stomach upset, feeling faint and/or an increased heart rate are all indicators that your condition is getting worse.

If not treated, your condition will decline further. Dizziness and/or nausea will likely follow. Your skin will change from red to pale or blue-ish. Feeling hot will be replaced by feeling chilled. Convulsions are a possibility. In this state, the body begins to fail and all priority should be placed on reversing the situation.

Thousands of people die from hyperthermia each year. A study, reported in the Annals of Internal Medicine, followed the progress of patients admitted to intensive care units for heat stroke and found that nearly half of the patients died within a year—28 percent died after their release from the hospital. This shows that the effects of heat stroke put long-term stress on the body. But it also shows, most likely, that those who experience hyperthermia probably do so by making daily mistakes on the prevention side. So let’s look at how to avoid hyperthermia on a daily basis and what to do when we slip up.

Daily strategies

Hydration is the key. A properly hydrated body will not be hyperthermic. But hydration can be tricky, especially as outside conditions change. Reacting to weather changes requires more than consuming your recommend 6 to 8 glasses of water per day. This is because water is only one side of the equation. Body salts, called electrolytes, are the other side. The primary electrolyte is one of the more misunderstood nutrients on the planet: salt.

Staying hydrated requires that you keep a balance of water and salt. As we heat up, our requirements for both of these increase. The standard requirement of 6 to 8 glasses of water per day can change to per hour under extremely hot conditions when you’re exercising. Salt can be even more confusing. The recommended daily allowance (RDA) for sodium is 2,500 milligrams per day. But a person sitting inside in cool temperatures may only need 500 milligrams per day, whereas someone exercising in the heat may sweat out 2,000 milligrams in 1 hour! This means that the RDA is a random number based on an average. How much salt you need is directly related to your lifestyle and the weather. The more you sweat, the greater your need for salt.

Too much salt and not enough water is a deadly condition that most of us are aware of, but too much water and not enough salt will kill you even more quickly. Since most of us have plenty of salt in our daily diets (and millions of us too much), we tend to focus mainly on water intake for staving off dehydration. But ensuring that you have a balance of water and electrolytes becomes vital as the temperature rises.

While confusing, this dilemma isn’t all that hard to sort out. There is a great margin for error when it comes to hydration, and it’s not vital to get it perfect, unless you’re competing in a sport. For most of us, just being aware that we’re drinking extra water and getting some salt in our diets as demands on hydration increase is enough. Sweating is an easy way to tell that you’re getting this right. If you’re sweating in the heat, you’re doing something right. Beginning to cramp is a sign that you’re out of balance one way or another and a simple solution is to add more of the one you’ve been consuming the least, be it water or salt. For most of us, it will be water, but if you exercise a lot or eat a low-sodium diet, it may be salt. This unscientific protocol is perfectly adequate to keep most of us functioning fine through the summer.

When it gets hot

We’re pretty good at adjusting to heat over time. By far, we’re at most risk when the weather initially changes. It takes around 5 to 7 days to adjust to living in elevated temperatures. During this period, your body undergoes a series of changes that makes continued exposure to hot conditions more endurable. If you handle the adjustment carefully, you’re most likely set for the season, save for those times you choose to put yourself in an exposed situation.

Obviously, hydrating well during these periods is vital, but other methods of staying cool should also be considered. Covering exposed skin with light-colored, loose-fitting clothing is helpful, as is using sunblock liberally on all exposed areas. Nothing makes this transition more challenging than allowing your skin to get burnt on your first day in the sun. This is also hat season. Your scalp is susceptible, even if you have a lot of hair.
Applying Suntan Lotion and Baby Wearing a Hat at the Beach

If you do get burnt, keep your skin bathed in lotion and out of the sun. If you’re forced outside for hours on end, especially doing something physical, consider dumping water over your head or on your neck every so often. Continually exposing your body to something cold will keep your body core temperature low and cardiac drift (a state wherein you heart beats faster to keep up with a climbing body temperature) from occurring.

Dealing with acute situations

Once you’ve become overheated, you want to reduce your body temperature as quickly as you can. This has been debated over the years. In fact, during the 19th century, public pumps had warning signs stating that drinking cold water during excessive heat could kill you. Modern and recent studies have shown the opposite. First, that “it’s quite difficult, if not impossible” to kill someone by cooling them quickly when they’re overheated, and second, that the quicker you can cool someone off, the faster they will recover.

Cold-water immersion is the most effective way to lower a high body temperature. Of course, it’s not always practical or possible but any step in this direction will help alleviate the situation. If nothing cold is accessible, use whatever is available. Warm water on the skin, or almost anything damp, will still create convection with the air and mimic sweat. Getting to the shade or covering all exposed skin helps, too.

If the situation is dire, or prolonged exposure to heat has occurred, medical advice should be sought out, even if the situation seems under control. Excessive exposure can cause trauma that’s not always apparent, and some amount of medical support, like an IV drip of electrolyte solution, can keep the body from incurring any long-term damage.

Maurice Ndukwu, of the University of Chicago Medical Center, warns that heat stroke is more serious than it’s often given credit for. In the Annals of Internal Medicine he states, “Classic heat stroke is a deadly disorder, more complex, more often fatal, and more permanently disabling than the literature on this order would predict. This [study] drives home the crucial importance of prevention and rapid diagnosis and treatment.”

Source: Casa D. J.; McDermott, B. P.; Lee, E. C.; Yeargin, S. W.; Armstrong, L. E.; Maresh, C. M. “Cold Water Immersion: The Gold Standard for Exertional Heatstroke Treatment.” Exercise and Sport Sciences Reviews: July 24, 2007.


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