Hypothermia is a condition everyone should be informed about, especially those of us fond of spending a lot of time in the great outdoors. It is associated with frigid weather in most people’s minds, but a significant drop in body temperature can occur even in temperate weather under certain conditions. Hypothermia is about more than a bad case of the shivers. In some cases it can be life threatening, so it is important to understand what causes it and how to protect your self from experiencing it. Let’s explore the subject a bit, and see what we come up with.
What is Hypothermia?
In a nutshell, hypothermia (literally meaning “low heat”) can be boiled down to a simple mathematical equation: The amount of heat your body is able to produce is less than the amount that escapes your body. Therefore, body temperature drops below normal, and when this happens, it has affects that can produce both physical and mental symptoms. Minor cases of hypothermia are simply uncomfortable or annoying, but severe hypothermia, or moderate cases in high risk individuals, can result in a serious medical emergency or even death.
Hypothermia is not particularly common in modern times, mainly due central heat in homes and the availability of warm clothing for most people. While some hypothermia occurs in people who are working or recreating outdoors, most cases in the United States are found in individuals that are elderly, homeless, or impaired by alcohol or drugs. In fact, homeless male alcoholics compose the largest demographic group that is affected by serious or fatal cases of hypothermia.
Statistics tell us that there are about 700 deaths annually in the US from hypothermia, with a recent 15 year period producing almost 12,000 fatalities. This is a relatively small number considering the overall population, but these figures should alert us to the possible consequences of a dangerous drop in body temperature, which may occur suddenly or gradually. Many victims are surprised at how easily hypothermia can occur. Exposure to frigid waters is especially hazardous, as the body loses heat much more rapidly in water than in air, but keep in mind that any body of water under 70F has the potential to produce hypothermia.
What Causes Hypothermia?
Normal oral body temperature ranges from 97F to 100F, with the average being 98.6F. Officially, hypothermia is diagnosed when the core or inner body temperature drops below 95F (35C). Our bodies are created with a marvelous temperature control system that is the envy of any heating / cooling system engineer. Metabolism is the process whereby the body utilizes energy to produce heat, and functions such as perspiration and respiration are in place to eliminate excess heat and maintain a proper body temperature.
When the core body temperature starts to drop below normal, our bodies respond by boosting metabolism to produce more heat energy. Shivering is one example of this. However, if the loss of heat is too great, or the mechanisms that regulate temperature are not working efficiently, the scales may tip in the direction of a cooler body temperature. This heat drain technically becomes hypothermia once the temperature falls below 95F, but even readings below 97F can cause trouble for some individuals. Examples include an elderly person that lives extended periods of time in a cold house. While their temperature may not immediately fall below 95F, a cumulative effect can occur which may eventually lead to hypothermia.
Hypothermia can be classified into two major types: Primary and secondary.
Primary hypothermia is the most common form, and it is induced when environmental factors such as cold air or water cause the associated drop in body temperature. Cold air exposure is usually a slower acting factor in hypothermia. However, some of the most dangerous cases of hypothermia can occur when cold water is the agent. Cold water exposure may be combined with cold air or windy conditions, such as being unexpectedly caught in a thunderstorm that soaks your clothing. It may also take the form of sudden contact with cold water such as in a boating or automobile accident. Other than individuals that pass out or fall asleep in frigid weather, cold water exposure can quickly cause some of the most dangerous hypothermic situations. Even in the spring or summer, cold waters such as those in Lake Superior or certain oceanic waters can result in life threatening hypothermic reactions in a matter of minutes. Secondary hypothermia involves a malfunction of the temperature maintenance functions of the body. This can occur due to many factors. Some of the most common include:
- Brain or spinal chord damage
- Certain bacterial infections (such as meningitis or encephalitis)
- Hypothyroidism (an under active thyroid gland)
- Circulatory disorders
- Certain Medications
- Alcohol: The effects alcohol has on body temperature deserves special mention, as it is involved with many fatalities involving hypothermia. Alcohol usage is risky in cold weather for a few reasons. First, when under the influence, a person may not exercise good judgment when it comes to exposure to a frigid or cold, damp environment. Secondly, one of the physiological effects of alcohol is to dampen or totally shut down the body’s built in devices for regulating temperature. Thirdly, intoxicated individuals are susceptible to passing out or falling asleep in dangerously cold weather. And finally, alcohol may deceive people into thinking it will keep them warm in cold temperatures, when in actuality it does just the opposite
Isolated individuals that are elderly or on certain medications are at particular risk for secondary hypothermia. As we age, our bodies do not respond as well to environmental temperature changes. Many senior citizens are not able to fight off hypothermia as well as younger people because their bodies are not able to shiver or narrow the blood vessels as efficiently. Combine this with the fact that many such folks may be taking medications or have conditions that increase the likelihood of hypothermia, and you have a very high-risk population. This is one reason why it is so important to check on the welfare of seniors or mentally handicapped individuals, especially in cold weather.
What Are the Signs and Symptoms of Hypothermia?
Symptoms of hypothermia generally start slowly, and gradually progress. However, in certain situations such as a plunge into an icy cold lake, hypothermia can develop very quickly. Signs to watch out for include:
- Shivering: While this is a normal and beneficial reaction designed to increase body temperature, excessive shivering can be a sign of hypothermia.
- Cold skin
- Paleness of skin
- Reduced rate of respiration (heart rate, respirations, and blood pressure may initially rise as the body attempts to warm itself, but once hypothermia begins to take hold, these will fall)
- Slurred or awkward speech
- Physical clumsiness
- Staggering or stumbling
- Blurred vision
- Apathetic attitude
- Irregular heartbeat
How is Hypothermia Best Treated?
The answer to this question is largely dependent on the degree of hypothermia. However, certain general guidelines exist:
Always warm individuals slowly. Never submerse a person in a hot bath or submit them to hot temperatures such as in a sauna, whirlpool, or steam room. No matter how minor or major the hypothermia, slower is always better. This is important for helping the body’s natural temperature mechanisms to begin operating again. It is also a protective measure against causing more harm to potential frostbite, one of the most common complications of hypothermia. Remove wet clothing: Getting a patient dry as soon as possible is a standing order when it comes to hypothermia. Wet only makes recovering from hypothermia more difficult. Handle with care: It is important to be gentle with those recovering from hypothermia. Rough handling can lead to cardiac complications that will disturb the normal rhythms of the heart. Rehydrate: If the patient is able to swallow safely, small amounts of warm liquids (nonalcoholic) will help restore fluids and warm them up.
When it comes to rewarming, let’s take a look at specific recommendations for mild, moderate, and severe hypothermia:
- Mild hypothermia: Use passive rewarming. This is a fancy way of saying let the victim get warm on their own. Once they have been removed from the elements and are wearing dry clothing, their own body can take over from that point.
- Moderate hypothermia: They may need a jump start, so to speak. Moderate cases call for active external warming, which may include the use of a heating pad, hot water bottle, or an electric blanket to warm the patient.
- Severe hypothermia: This is a true medical emergency that calls for immediate care. Severe cases may need active internal warming. Examples of this type of therapy include warming and recirculating the blood, or the introduction of warm oxygen and / or fluids into the body. Extreme measures such as these are used to resuscitate hypothermic individuals that may actually appear as if they have died.
How Can Hypothermia Be Prevented?
Not all cases can be prevented as nobody can predict when an unforeseen accident may occur. However, there are several common sense steps that can be taken to minimize risk for hypothermia:
- When outdoors, make sure you have enough food and water. Staying hydrated and having ample calories in your system will help your natural temperature regulating mechanisms to work at their optimal best.
- Dress in layers in order to stay warm and still have the ability to remove clothing so that you don’t get too warm. This will help keep you from perspiring in cold weather too, which can bring on hypothermia or worsen an existing condition
- Don’t underestimate warm weather dangers: People have died from hypothermia in spring or summer by being caught in a rain storm or a fast moving cold front. When spending time in the outdoors, always plan for the unexpected.
Good old fashioned “horse sense” can prevent many cases of hypothermia. In dangerously cold weather, don’t forget to check on those who may be especially at risk. Our elderly friends and neighbors may need a little extra attention during such times to make sure they “weather” it well.