Hypothermia

Hypothermia is low body temperature. The commonly accepted average normal body temperature is 98.6° F (37° C). When the body temperature drops below 95° F (35° C), it is a medical emergency.

CAUSES

Hypothermia usually occurs when a person is exposed to low temperatures. Such exposures frequently occur when a person does not have proper shelter or clothing. This can occur when a person is stranded outside, homeless, does not have heat in his or her home, or is immersed in cold water. People with impaired mobility, babies, and the elderly are particularly susceptible to becoming hypothermic. Sometimes the body's temperature control can be altered by disease. Certain medical conditions increase a person's risk of developing hypothermia, including:

  • Burns.

  • Lasting (chronic) skin disease (psoriasis).

  • Head injuries.

  • Strokes.

  • Poisonings.

  • Parkinson's disease.

  • Brain tumors.

  • Multiple sclerosis.

  • Inflamed pancreas (pancreatitis).

  • Overwhelming infections.

  • Uremia.

  • Alcoholism.

  • Substance abuse.

  • Mental illness.

  • Certain medicines.

SYMPTOMS

  • Drowsiness.

  • Confusion.

  • Slowed thinking and speech.

  • Slow, shallow breathing.

  • Slow, weak pulse.

  • Shivering (early in hypothermia) or no shivering (late in hypothermia).

  • Uncoordinated movements.

  • Slowed response time.

  • Numbness.

DIAGNOSIS

Hypothermia is usually suspected when someone has been exposed to cold. It is verified by taking the person's temperature with a thermometer. The most accurate measurement is a rectal temperature.

TREATMENT

Treatment begins with first aid on the scene. If hypothermia is suspected, treatment should be gentle. Vigorous handling can cause the heart to stop. Attempt first aid until it is possible to transport the person to a medical facility for further help. First aid on the scene includes:

  • Moving the person to a warmer location. If you cannot get the person inside, protect him or her from the wind. Lay him or her on a cloth, blanket, sleeping bag, or even cardboard, so that he or she is not in contact with the cold ground.

  • Taking off the person's wet clothes. Wrap him or her in warm, dry material, such as blankets, coats, towels, sleeping bags, or clothing. If you cannot get the person to medical help right away, lie down close to the person. Sharing body heat, especially skin-to-skin contact, can help raise his or her body temperature.

  • Giving the person a warm drink. Do not give alcohol or caffeine.

  • Using first-aid warm compresses to provide heat to the neck, chest, or groin. Do not apply the compress to the arms or legs, as this can cause a fatal heart attack.

Never use a heat lamp, heating pad, or hot water to apply heat directly to a person who is hypothermic. This can injure his or her skin or cause a heart attack.

Once the person is taken to a medical facility, a variety of treatments can be done, including:

  • Giving warm fluids by intravenous (IV) access.

  • Giving warm, humidified oxygen through nasal tubing (nasal cannula), an oxygen mask or a breathing tube (endotracheal tube).

  • Rewarming the blood by removing it, passing it through a hemodialysis machine, and returning it to the body at gradually increasing temperatures.

  • Inserting a tiny tube into the stomach, bladder, or intestine, and instilling a warm saline solution directly into the body cavity. This is called cavity lavage.

HOME CARE INSTRUCTIONS

If you have a condition that may make you prone to hypothermia, be sure to keep your home warm. When you are in a cold environment, wear layers of clothing. People lose a lot of heat from the head and hands, so always wear a hat and gloves in the cold. Find out whether any of your medicines may put you at risk for hypothermia. Do not drink alcohol if you will be in the cold. Alcohol causes your blood vessels to get larger (dilate), making you lose body heat.

SEEK IMMEDIATE MEDICAL CARE IF:

  • You start to shiver.

  • Your teeth chatter.

  • You become drowsy.

  • You become confused or have slowed thinking and speech.

  • You develop slow, shallow breathing.

  • You develop a slow, weak pulse.

  • You have decreased coordination.

  • Your response time is slow.