When exposed to cold temperatures, your body begins to lose heat faster than it can be produced. Prolonged exposure to cold will eventually use up your body's stored energy. The result is hypothermia, or abnormally low body temperature. Body temperature that is too low affects the brain, making the victim unable to think clearly or move well. This makes hypothermia particularly dangerous because a person may not know it is happening and won't be able to do anything about it.
Hypothermia is most likely at very cold temperatures, but it can occur even at cool temperatures (above 40°F) if a person becomes chilled from rain, sweat, or submersion in cold water.
Victims of hypothermia are often (1) elderly people with inadequate food, clothing, or heating; (2) babies sleeping in cold bedrooms; (3) people who remain outdoors for long periods?the homeless, hikers, hunters, etc.; and (4) people who drink alcohol or use illicit drugs.
Warnings signs of hypothermia:
- shivering, exhaustion
- confusion, fumbling hands
- memory loss, slurred speech
- bright red, cold skin
- very low energy
What to Do
If you notice any of these signs, take the person's temperature. If it is below 95°, the situation is an emergency?get medical attention immediately.
If medical care is not available, begin warming the person, as follows:
- Get the victim into a warm room or shelter.
- If the victim has on any wet clothing, remove it.
- Warm the center of the body first ? chest, neck, head and groin ? using an electric blanket, if available. Or use skin-to-skin contact under loose, dry layers of blankets, clothing, towels, or sheets.
- Warm beverages can help increase the body temperature, but do not give alcoholic beverages. Do not try to give beverages to an unconscious person.
- After body temperature has increased, keep the person dry and wrapped in a warm blanket, including the head and neck.
- Get medical attention as soon as possible.
A person with severe hypothermia may be unconscious and may not seem to have a pulse or to be breathing. In this case, handle the victim gently, and get emergency assistance immediately. Even if the victim appears dead, CPR should be provided. CPR should continue while the victim is being warmed, until the victim responds or medical aid becomes available. In some cases, hypothermia victims who appear to be dead can be successfully resuscitated.
Frostbite is an injury to the body that is caused by freezing. Frostbite causes a loss of feeling and color in affected areas. It most often affects the nose, ears, cheeks, chin, fingers, or toes. Frostbite can permanently damage the body, and severe cases can lead to amputation. The risk of frostbite is increased in people with reduced blood circulation and among people who are not dressed properly for extremely cold temperatures.
At the first signs of redness or pain in any skin area, get out of the cold or protect any exposed skin?frostbite may be beginning. Any of the following signs may indicate frostbite:
- a white or grayish-yellow skin area
- skin that feels unusually firm or waxy
A victim is often unaware of frostbite until someone else points it out because the frozen tissues are numb.
What to Do
If you detect symptoms of frostbite, seek medical care. Because frostbite and hypothermia both result from exposure, first determine whether the victim also shows signs of hypothermia, as described previously. Hypothermia is a more serious medical condition and requires emergency medical assistance.
If (1) there is frostbite but no sign of hypothermia and (2) immediate medical care is not available, proceed as follows:
- Get into a warm room as soon as possible.
- Unless absolutely necessary, do not walk on frostbitten feet or toes?this increases the damage.
- Immerse the affected area in warm?not hot?water (the temperature should be comfortable to the touch for unaffected parts of the body).
- Or, warm the affected area using body heat. For example, the heat of an armpit can be used to warm frostbitten fingers.
- Do not rub the frostbitten area with snow or massage it at all. This can cause more damage.
- Don't use a heating pad, heat lamp, or the heat of a stove, fireplace, or radiator for warming. Affected areas are numb and can be easily burned.
These procedures are not substitutes for proper medical care. Hypothermia is a medical emergency and frostbite should be evaluated by a health care provider. It is a good idea to take a first aid and emergency resuscitation (CPR) course to prepare for cold-weather health problems. Knowing what to do is an important part of protecting your health and the health of others.
Taking preventive action is your best defense against having to deal with extreme cold-weather conditions. By preparing your home and car in advance for winter emergencies, and by observing safety precautions during times of extremely cold weather, you can reduce the risk of weather-related health problems.
Hypothermia happens when a person's core body temperature is lower than 35°C (95°F). Hypothermia has three levels: acute, subacute, or chronic.
- Acute hypothermia is caused by a rapid loss of body heat, usually from immersion in cold water.
- Subacute hypothermia often happens in cool outdoor weather (below 10°C or 50°F) when wind chill, wet or too little clothing, fatigue, and/or poor nutrition lower the body's ability to cope with cold.
- Chronic hypothermia happens from ongoing exposure to cold indoor temperatures (below 16°C or 60°F). The poor, the elderly, people who have hypothyroidism, people who take sedative-hypnotics, and drug and alcohol abusers are prone to chronic hypothermia, and they typically:
- misjudge cold
- move slowly
- have poor nutrition
- wear too little clothing
- have poor heating system
Causes of Hypothermia
- Cold temperatures
- Improper clothing, shelter, or heating
- Fatigue, exhaustion
- Poor fluid intake (dehydration)
- Poor food intake
- Alcohol intake
- Everyone, especially the elderly and ill, should have adequate food, clothing, shelter, and sources of heat.
- Blankets can help, even in poorly heated rooms.
- Wear layers of clothing and a hat, which help to keep in body heat.
- Move around. Physical activity raises body temperature.
Water cooler than 75°F (24°C) removes body heat more rapidly than can be replaced. The result is hypothermia. To avoid hypothermia:
- Avoid swimming or wading in water if possible.
- If entering water is necessary:
- Wear high rubber boots in water.
- Ensure clothing and boots have adequate insulation.
- Avoid working/playing alone.
- Take frequent breaks out of the water.
- Change into dry clothing when possible.
Helping Someone Who Is Hypothermic
As the body temperature decreases, the person will be less awake and aware and may be confused and disoriented. Because of this, even a mildly hypothermic person might not think to help himself/herself.
- Even someone who shows no signs of life should be brought quickly and carefully to a hospital or other medical facility.
- Do not rub or massage the skin.
- People who have severe hypothermia must be carefully rewarmed and their temperatures must be monitored.
- Do not use direct heat or hot water to warm the person.
- Give the person warm beverages to drink.
- Do not give the person alcohol or cigarettes. Blood flow needs to be improved, and these slow blood flow.
For more information about hypothermia, see Extreme Cold: A Prevention Guide to Promote Your Personal Health and Safety.