The Two Types of Hypothermia

Hypothermia describes a condition where the body’s core temperature drops below 95 degrees Fahrenheit. Human beings, lacking a protective outer layer of fat or fur, have a difficult time in cold environments without proper clothing, and hypothermia can be the tragic result. Recently, in Oregon, a father left his stranded vehicle to find help for his family in the cold environs of the mountainous wilderness, and perished from hypothermia. It is not just bitter cold temperatures though that can cause the drop in body temperature that precipitates hypothermia, a condition that kills some seven hundred Americans each year. Many people can get hypothermia in their own homes!

Several of the chemical reactions that are needed for humans to survive require a certain temperature range, and when people cannot maintain that temperature, they can fall victim to hypothermia. A person’s temperature fluctuates between 97 and 100 degrees, as individuals balance the heat that is produced through metabolism with the heat lost through the skin and lungs to the outside world. But when heat loss outstrips heat production, the brain tries to compensate for the disparity in a number of ways. Shivering helps to produce heat; this involuntary muscle action speeds up metabolism. But as the body remains exposed to cold, shivering stops, oxygen consumption begins to fall, and the heartbeat becomes irregular as hypothermia takes it toll.

There are two types of hypothermia, primary and secondary. Primary hypothermia happens to people with normal heat-balancing apparatus in fine working order who are exposed to extreme cold, while secondary hypothermia occurs when someone’s heat-balancing mechanism is impaired by disease or some other condition, making it possible for moderate or mildly colder temperatures to adversely affect them. Strokes, diabetes, infection, malnutrition, alcoholism, thyroid disease, and the use of certain medications put you at risk for secondary hypothermia. Alcohol can short circuit a person’s heat-balancing system by shutting it down when consumed in large amounts, while it can make them unable to recognize that they are in peril when taken in smaller quantities. The elderly are especially vulnerable to secondary hypothermia, as they have a harder time conserving heat and often suffer from conditions that make them more susceptible to its effects, such as malnutrition and being bedridden. Shivering and the narrowing of blood vessels are two of the body’s major defenses against the cold, something that is not initiated as rapidly in many elderly people. This makes it possible for older citizens to develop hypothermia over the course of days and weeks if their home is poorly insulated, while those around them fail to realize what is happening, even when the temperature is as high as sixty degrees! Hypothermia in the elderly in such situations is often misread as another problem such as a stroke or other ailments that are common to people of that age.

One rule of thumb in determining if someone up there in years is afflicted by secondary hypothermia is to be wary of what are known as the “umbles”. Stumbling, mumbling, fumbling, and grumbling can all mean that an elderly person is suffering from the effects of secondary hypothermia, as the cold begins to work on their muscles and coordination. Other symptoms include the person being confused and sleepy, shallow breathing, slurring their words, and muscle stiffness. Their behavior may seem odd and their blood pressure can be low. If a room or rooms in the house seem chilly, do not dismiss the possibility that secondary hypothermia could be causing these symptoms.
If you are in one of the high risk groups for secondary hypothermia, avoid cold places. Your body may have a hard time recognizing the change in temperature until it is too late, or it may never makes the distinction. Be sure to maintain good nutrition, so you will need that layer of fat under your skin that can protect your body. Illnesses such as hypothyroidism, diabetes, and psoriasis make it more difficult for your body to stay warm. Wear layers of clothing even indoors in the cold months and use extra blankets at night. Do not wear tight clothing; loose clothing traps warm air between the layers, while tight clothing can disrupt blood flow. Talk to your physician about the effects that whatever medicines you may be taking regularly have on your body heat. Avoid alcohol, as it can make your body lose heat even faster than normal.

Primary hypothermia usually involves a person being out in the very cold or falling into cold water. Water will rob the body of heat twenty-five times faster than the surrounding air will, so someone who falls through the ice, for example, needs to extricate themselves quickly and find shelter and warmth or they will develop hypothermia in short order. Hypothermia happens in stages, and the body temperatures at which each stage takes place will differ from person to person depending on factors such as age, fitness, and even size. As the core temperature of the body reaches the 95 degree range, a lack of coordination is quite noticeable, and the skin will be cold and pale-looking as the person shivers violently. Shivering shuts down between 90 and 86 degrees; speech will become slurred, muscles become stiff, and the person will be confused and disoriented and have a hard time seeing. The liver and kidneys are now at high risk of experiencing failure and the person will suffer from dehydration. The majority of people whose core temperature drops below 86 degrees go into a coma, and after the 82 degree mark is passed the heart rate can be erratic and brain activity is slowed. Death is imminent, but there have been instances where people have been revived that were at this point, prompting the saying “not dead until warm and dead”!