What is hypothermia?

Hypothermia is an abnormally low body temperature brought on by staying in cold temperatures for a long period of time. This lowered body temperature affects the brain, and a person's ability to think clearly or move well. Severe hypothermia can also cause an irregular heartbeat leading to heart failure and death.

While hypothermia happens most often in very cold temperatures, even cool temperatures (above 40°F or 4°C) can be dangerous to a person who has become chilled from rain, sweat, or being in cold water for an extended period of time. 

Who is at risk for hypothermia?

The following people are most at risk for hypothermia:

• Elderly people, who often have other illnesses, such as hypothyroidism, heart disease, or circulation problems, or take medicines that interfere with the body's ability to regulate its temperature

• Elderly people with inadequate food, clothing, or heat; often these people sit alone for hours or days at a time in a cold apartment or home; improper nutrition also makes them more susceptible to the cold

• Infants and toddlers sleeping in cold bedrooms

• People who stay outdoors for long periods of time, such as the homeless, hikers, and hunters

Half of the elderly people who develop hypothermia die before, or soon after, being found. However, even young, seemingly strong people, are affected by hypothermia when exposed to the cold for long periods of time.

What are the symptoms of hypothermia?

The following are the most common symptoms of hypothermia:

• Confusion

• Sleepiness

• Fumbling hands

• Shivering and exhaustion

• Slow, slurred speech, or shallow breathing

• Weak pulse and/or low blood pressure

• Drowsiness

• A change in behavior or appearance during cold weather

• Stiffness in the arms and legs

• Poor control over body movements or slow reactions

• In infants, bright red, cold skin and/or very low energy

To determine if the person is suffering from hypothermia, take his or her temperature with a thermometer. A body temperature under 95°F (35°C) is a medical emergency and can be fatal if not promptly treated. If the person has symptoms of hypothermia and a temperature cannot be taken, call 911. 

What should you do while waiting for medical attention?

It is important that victims of hypothermia receive immediate medical attention. While waiting for medical attention, some methods of dealing with a hypothermia victim include the following:

• Seek medical attention as soon as possible.

• Get the victim into a warm room or shelter.

• If he or she has on any wet clothing, remove it immediately.

• Warm the center of the body first—the chest, neck, head, and groin—using an electric blanket, if it is available. Or use skin-to-skin contact, with your own body heat providing warmth to the victim.

• Be careful to not handle the victim roughly.

• Warm beverages can also be helpful, but never give a victim of hypothermia any alcoholic beverage, and never try to give an unconscious person something to drink.

• Once the body temperature begins to increase, keep the person dry and wrapped in warm blankets.