Cold-related injuries, such as hypothermia and frostbite, occur when low temperatures damage the body. In hypothermia, the body's internal temperature falls, causing blood flow and breathing to get dangerously slow. In frostbite, outer parts of the body, such as fingers and toes, start to freeze. Other cold-related injuries include chilblains and trench foot.
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Hypothermia
Who Is at Risk for Cold-Related Injuries?
Anyone who spends time outdoors in cold weather can be at risk for cold-related injuries. That includes people who fish, hunt, or hike, especially in the mountains, where temperatures can drop quickly and icy rain or snow can blow in with little warning. In snowstorms, people trapped in their cars can suffer permanent injury or even death, if they cannot keep warm until help arrives.
In cities, homeless people who remain outdoors in the cold are at special risk. So are poor people who cannot afford to heat their homes or whose landlords do not provide heat.
Indoors or outdoors, elderly people, the very young, and those who abuse alcohol or drugs also are at extra risk. Hypothermia, in which body temperature falls, is most common in cold, wet weather. But with elderly people, especially, it can occur at temperatures as high as 65 degrees Fahrenheit, coming on gradually over days. That's because aging can reduce the body's ability to conserve heat and maintain an internal (core) temperature of about 98.6 degrees. In addition, elderly people may not feel the cold as much and so may not take steps to get warm.
In the United States, from 500 to 1,000 people are known to die each year from the cold. But doctors suspect that thousands of elderly people may be hospitalized each year for problems caused by undiagnosed hypothermia.
What Is Frostbite?
Frostbite is the freezing of any part of the body. Ice crystals form within or between the cells. Red blood cells and platelets clump and restrict blood flow, especially to the ears, fingers, toes and nose. These areas usually are the first to turn cold, white, hard, and numb. Frostbite can be deceptive—because it causes numbness, rather than pain, people may not know it is happening in time to prevent serious damage.
Weather and Warfare
Throughout history armies faced the perils of winter weather. George Washington at Valley Forge (1777—1778) lost many men to the cold. Napoleon, after first successfully invading Russia in 1812, was forced to retreat from the walls of Moscow when his army faced the terrible Russian winter.
How Is Frostbite Treated?
In dealing with frostbite, doctors usually recommend that the affected body parts be warmed rapidly in warm, not hot, water. Rubbing the frostbitten parts is not advisable because more tissue damage can be caused by this process. Another myth is that the frostbitten area should be rubbed with snow. This can also cause more damage.
Thawing is occurring when the affected part begins to become pink or red. If it remains white that means more time has to be allowed for thawing in the warm water.
Small blisters appear right after the rapid thawing. They break in about a week. A black scab forms after the blisters rupture. Normal tissue may have already formed below. The thawed part is usually protected to avoid both refreezing and excessive heat. Usually neither bandages nor dressings are used, and the area is cleaned with mild soaps.
A doctor will recommend exercises to preserve joint motion in hands and feet. Early surgical removal of the dead tissue may save the part from amputation. Antibiotics are prescribed, if necessary.
What Is Hypothermia?
Hypothermia (hy-po-THER-mee-a) is the lowering of the body temperature below 35 degrees Centigrade. It results from prolonged exposure to cold when the body heat loss is greater than heat production. Hypothermia can be life-threatening. As in the case of frostbite, the sooner the affected person receives treatment the better the chances for survival.
The Wind-Chill Factor
The wind-chill factor can increase heat loss from the body. If the skin is wet, there is an even greater transfer of heat to the surrounding air from the body. Those who are at risk from these circumstances are people who fish on ice, hunters, skiers, campers, and hikers in the mountains. Anyone exposed to wind and low temperatures can develop serious frostbite.
The actual temperature and the wind speed determine the wind-chill temperature. The lower the wind-chill temperature, the greater risk to human beings.
Temperature 35°F 15°F 0°F -15°F
Wind Speed 10 mph 20 mph 30 mph 45 mph
Wind Chill
Temperature 22°F -17°F -49°F -78°F
What Are the Symptoms of Hypothermia?
Some of the symptoms of hypothermia are slurred or incoherent speech, a drop in the level of awareness, irritability, slowed rate of breathing, and violent shivering. When shivering stops, it indicates exhaustion, and the body temperature drops even more rapidly. Children and the elderly are more susceptible to hypothermia, because their body temperature drops more rapidly.
a Cold Ride
A description of what it might feel like to freeze can be found in These Happy Golden Years by Laura Ingalls Wilder, which takes place in the Dakota Territory in the early 1880s. Almanzo Wilder, a young man who owns a sleigh and two horses, undertakes to drive Laura Ingalls home for the weekend from the place where she teaches school. Unfortunately a storm is brewing; the wind blows hard, and the thermometer has dropped to 40 below zero and is frozen there:
The cold was piercing through the buffalo robes. It crept through Laura's wool coat and woolen dress, through all her flannel petticoats and the two pairs of woolen stockings drawn over the folded legs of her warm flannel union suit … In spite of all she could do, Laura shook all over. Pressing her knees tight together did not stop their shaking. The lantern beside her feet under the fur robes seemed to give no warmth. The pains bored into her temples, and a knot of pain tightened in her middle.
But Almanzo does not get worried about her until she starts to feel sleepy:
She was growing more used to the cold. It did not hurt so much. Only the pain in her middle kept tightening, but it was duller. The sound of the wind and the bells and the cutter's runners on the snow all blended into one monotonous sound, rather pleasant.…
"All right?" he asked. She nodded. It was too much trouble to speak.
"Laura!" he said, taking hold of her shoulder and shaking her a little. The shaking hurt; it made her feel the cold again. "You sleepy?"
"A little," she answered.
"Don't go to sleep. You hear me?"
"I won't," she said. She knew what he meant. If you go to sleep in such cold, you freeze to death.
In reality, going to sleep in the cold does not cause a person to freeze to death, although moving the body, more likely to occur when a person is awake, helps generate body heat. The sleepiness is a symptom of severe hypothermia (low body temperature), and asleep or not, Laura and Almanzo are certainly in danger of freezing.
One reason that Laura Ingalls Wilder excelled at describing the cold realistically is that her stories are true; she is recording her own experience. Another one of her novels is called The Long Cold Winter.
Irritable behavior may be a sign of hypothermia. Aside from comments about being cold, hypothermia symptoms may emerge in the form of anger or inability to perform physical movements. Severe hypothermia may produce rigid muscles, dark and puffy skin, irregular heart and respiratory (breathing) rates, unconsciousness, and eventually death.
How Is Hypothermia Treated?
Hypothermia is treated by keeping the patient warm and by getting immediate medical attention. If wet, the clothes are removed carefully. The skin is not rubbed. If the person is unconscious and not breathing, cardiopulmonary resuscitation (CPR) should be attempted by someone who has been trained in this revival technique.
What Are Trench Foot and Chilblains?
Trench foot is a painful disorder of the foot involving damage to the skin, nerves, and muscle that is caused by prolonged exposure to cold or dampness or by prolonged immersion in cold water. The soldiers fighting in the trenches during World War I developed this painful condition because they did not have access to clean, dry socks and boots.
Chilblain (CHILL-blain; often referred to in the plural, "chilblains") usually affects the fingers and is characterized by redness, swelling, and itchiness caused by exposure to damp cold. Tissue damage is less severe with chilblains than with frostbite, where the skin is actually frozen. Chilblains do not cause permanent damage.
Can Frostbite and Hypothermia Be Prevented?
It is important to dress properly in cold, damp weather. Wearing several layers of dry, loose-fitting clothing that allow perspiration to evaporate is important. Exposed flesh should be protected from the wind. Face masks, hoods, and ear muffs are helpful. Hats are important because 30 percent of the body's heat is lost through the head. Gloves and socks should be kept dry. Consuming adequate amounts of food and fluid will help the body to generate heat.
It is also important to listen to highway department advisories about driving during snowstorms, since getting caught in a stalled car in a snowstorm can easily lead to frostbite and hypothermia.
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