Hypothermia: Who’s Most at Risk for This Cold-Weather Danger?
Be prepared in adverse weather—and avoid hypothermia: Cold weather kills more Americans each year, statistics show, than hot weather.
Cold weather can be hazardous for anyone, but particularly for older adults, because falling temperatures can cause hypothermia and frostbite, particularly if there are multiple days in a row in which the temperature drops below freezing. This makes it crucial for older adults to protect themselves from adverse weather and exercise extra caution especially during the winter.
How Hypothermia Happens
Your normal body temperature is around 98.6 degrees Fahrenheit (°F). Hypothermia occurs when your temperature falls below 95°F, and most cases are triggered outdoors by ambient temperatures below 59°F. Body temperature falls faster if there’s a wind chill and if your clothes are wet, but frail older adults may become hypothermic while indoors at temperatures as warm as 60 to 70°F.
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According to 2015 statistics from the Centers for Disease Control and Prevention, hypothermia killed more than 13,400 Americans between 2003 and 2013. That total may actually be an underestimate, since cold-related causes of death may not be listed on a death certificate due to difficulties in making such diagnoses.
Unless medical personnel are present at time of death, core body temperature generally is not known, and whoever is completing the death certificate may be unaware of extreme temperature exposures—for example, in an under-heated home— prior to a person’s death.
What Makes Older Adults So Vulnerable to Hypothermia?
Older adults are at greater risk for hypothermia because the body’s ability to maintain a constant internal temperature decreases with age. The elderly are less able to discriminate temperature changes, and are less able to generate heat in response to cold.
The body normally produces additional heat by shivering, and the blood vessels just under the skin’s surface constrict so that more blood goes to the heart and brain. But in older adults, this system doesn’t work as well.
A poor diet may exacerbate the risk by lowering your metabolic rate. And alcohol can be a factor, increasing blood flow to the skin and extremities and making you feel warm but increasing heat loss from your core.
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Frostbite results from tissue freezing: Ice crystals form and cause cells to die, with the most commonly affected areas being the ears, nose, cheeks, chin, fingers, and toes. You’re particularly vulnerable to frostbite if you have heart disease, diabetes, or other circulatory problems, and/or take beta-blockers, which decrease the flow of blood to the skin. Other drugs that increase the risk include antidepressants, opioids, and hypoglycemics. Clothing that doesn’t insulate or cover you well, or is damp, tight, or not windproof, can predispose to frostbite, as can excessive hand or foot sweating.
Conditions That Can Increase Risk of Hypothermia
Other health conditions also make you vulnerable because they further affect your body’s ability to regulate temperature. For example, an underactive thyroid causes decreased heat production, while chronic conditions that affect mobility (for example, arthritis) or cognitive function (such as Alzheimer’s disease) also can be factors. If you don’t move enough, you don’t generate enough compensatory body heat to make up for what’s being lost, while dementia may result in self-neglect—for example, you may go outside wearing indoor clothes.
Additionally, older adults may take medications (including some antidepressants, antipsychotics, and cardiac drugs) than can affect the body’s ability to regulate its temperature. Seniors also are at a higher risk of falls, which can lead to prolonged exposure, such as lying on a cold floor; and because many are on fixed incomes, they may have difficulty paying for heating.
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Hypothermia and Other Health Conditions
Other chronic health conditions—particularly cardiovascular disorders—affect how seriously hypothermia may compromise your health and well-eing. Research suggests that people age 75 and older are at an elevated risk for serious heart complications in cold weather, along with those who have previously diagnosed heart disease, or cardiovascular risk factors such as high blood pressure.
Irregular cardiac rhythms are the most common cause of death in hypothermia. The elderly are at greater risk for developing these rhythm disturbances and not responding to treatment, because as a general rule, their hearts are not as healthy.
Research has indicated that the risk of heart attack rises when the temperature drops. Temperatures in the region of 53°F are most risky (temperatures around 70°F are associated with the lowest cardiovascular mortality rate in the U.S.).
It isn’t clear exactly how cold weather leads to more heart attacks, but possible explanations include an increase in blood clotting and thickness as the body cools. Blood vessels also narrow in response to colder temperatures, and this causes a rise in blood pressure in order to move blood through the narrowed vessels. The strain of shoveling snow and other outdoor exertion also may be factors.
Another chronic condition that can be impacted by cold weather is chronic obstructive pulmonary disease (COPD). You may find that shortness of breath and sputum production (main symptoms of COPD) worsen when the mercury drops below freezing, and being outside may drain your energy more than usual.
STAYING WARM IN WINTER
One of the main red flags for hypothermia is shivering, although if the condition occurs in older adults inside, in less extreme temperatures (like an under-heated home), shivering may be absent.
Other signs that you may be becoming dangerously cold include slurred speech, lack of coordination and stumbling, drowsiness and apathy, rapid breathing, confusion and irritability. However, you may not actually realize that you have hypothermia. The symptoms creep up gradually, and the fact that an older adult’s ability to discriminate temperature changes is diminished means they may not respond appropriately. These factors mean that prevention is the most important thing to consider when it comes to avoiding hypothermia.
- If you can, try to avoid going out in extreme cold, particularly if it’s windy, as this increases the rate of heat loss from the skin.
- If you do need to go out, dress appropriately. Several light layers will keep you warmer than just one or two heavy layers, as each layer traps warm air, helping you retain body heat more effectively.
- Most body heat is lost through the head, so always wear a hat.
- Wear gloves, too—or better yet, mittens, which will keep your fingers warmer.
- If you get wet outside, remove wet clothing as soon as you can.
- Eating a healthy, nourishing diet also is important, since the body burns calories to generate body heat. If you’re undernourished, you may not be able to stay warm. If you’re having trouble preparing hot meals, contact your local senior center or Department of Aging office about meals on wheels. They also can advise about check-in services that arrange for someone to come and look in on you to make sure you are alright.
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Elderly people are especially at risk of hypothermia.
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