Hyperpyrexia- Signs, Symptoms, and Treatment

What is hyperpyrexia. What is heat stroke.

With summer fast approaching the North American Continent, it is critically important that Americans be prepared to prevent or at least minimize the risk of developing hyperpyrexia. This condition is also knows as heat stroke, high body temperature, and siriasis. It can be a life threatening condition if not recognized and treated immediately. This is a condition that can result in many other serious conditions including but not limited to kidney failure, stroke, and death. We will look at causes, systemic alterations, physiologic changes, and treatments.

Let's first look at what a heat stroke is. It is a serious condition that develops when the body over heats and looses the ability to cool itself down. When we go out on a hot day we loose a tremendous amount of water very quickly, not only from sweat, but also from our breaths. On an average day we loose between 500-1000 ml of water from our respiration alone. This is known as non-sensible loss. Every time we exhale, a fair amount of moisture goes with it. On a hot day, these losses can build exponentially.

This rapidly leads to dehydration. In order for the body to compensate, for this loss of water, it tells the body to stop sweating. It is the sweat that cools our bodies. Sweat is a critical component to our excretory system. It is responsible for the secretion of excessive salts and additional uric acid to be removed from out vascular spaces. With the onset of heat stroke, as our bodies begin to stop sweating, we can no longer excrete these salts. This in turn causes our internal pH to go more alkaloid. With alkalosis, our respiration increases significantly, leading to addition water loss.

As these salts build, it pulls additional water from out blood stream in order to dilute it down, this leads to renal failure and shutdown. Because the amount of water needed to properly function by the kidneys is drastically reduced or even completely shut off, our kidneys can no longer excrete waste. These toxins then build in the body. As we continue to loose more water, the blood concentrates as well as the waste and salt products. At this point, the cells in our bodies begin to shrink and rupture from the loss of water. Our blood becomes very hypernatremic (excessive sodium in the blood).

Often the blood can have excessive potassium, causing hyperkalemia as well. As this condition progresses, the person will have tachycardia (rapid heart rate), tachypnea (rapid breathing, typically shallow), confusion, altered mental status, agitation, seizures, nausea, and vomiting.

Now that you are planning your own experience with heat stroke, lets consider what are the main causes of heat stroke. Most often heat stroke is caused by going outdoors on a very hot day and engaging in vigorous activity. Or simply one does not plan or prepare for the rigors of excessive heat outdoors. If going outdoors it is imperative to be properly hydrated.


As a generalized rule, humans should drink around 2-3 liters of water daily. As the weather gets hotter this need is increase as well, this does not mean drinking 10 liters a day, but possibly up to 4-5, this also depends greatly on what you are doing outdoors. If lounging by the pool, then you will not need as much, but if working or playing football or basketball, this is the amount of fluids will need to increase. Make sure you have plenty of water in your vehicles as well; you never know if your car will overheat.

So what do you look for if a person is possibly having heat stroke? Exhaustion is typically the first sign the body is starting to overheat. This may also include rapid breathing (tachypnea), pale clammy skin (pallor), rapid heart rate (tachycardia) and profuse sweating (diaphoresis). These symptoms are indicated with heat exhaustion. This needs to be treated rapidly before the situation deteriorates into heat stroke. With heat exhaustion, take the person out of the sun, preferably into a cool room. If a cool room is not available, shade or a car. If in a car turn on the air conditioner, you will want the vents on the persons face chest, and lower extremities.

If it all possible. If in the shade, keep the person calm and resting, encourage small sips of water. Do not encourage gulps as this can cause significant cramping and vomiting. Sips are the best option here. Maybe even make a makeshift fan and fan the person for a few moments. Usually heat exhaustion does not require hospitalization.

Heat stroke is a different matter altogether. Treatments for heat stroke typically involve hospitalization. The person is treated with intravenous fluids in order to rehydrate fairly slowly, often sedation is required as the victim can become very agitated, in some cases, a bear hugger will be required. A bear hugger is a device that is used to cool or heat the human body as needed. In this case, it is set to cool. A person's torso and extremities are wrapped in sleeves and the bear hugger gently blows cool air through these sleeves. This results in the gradual cooling of the body.

One thing that is absolutely critical to keep in mind when it is hot out, do not drink alcohol. Many people get into serious trouble in hot weather, when they decide to cool off with a beer. Alcohol has the effect of dehydrating the body, so it will make the situation much worse. With the additional loss of water due to the alcohol, it will greatly exacerbate the effects of the alcohol.

So for example, one beer may have the physiologic effect of 3-4 beers, because of the decreased water in the body. It is important to always remain properly hydrated, but especially in the hot weather months. Take appropriate precaution such as don't go out unless necessary, avoid strenuous activity, drink plenty of water with an occasional sport drink, avoid alcohol, wear sunscreen, and of course wear a hat, this goes a long way to keep the heat away from the noggin. If you begin to feel or experience any of the above symptoms, please seek immediate medical attention. It may just save your life or your loved ones life.


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John Ferry
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Posted on Mar 19, 2011
john doe
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Posted on Mar 19, 2011