Your complete online medical source

Navigate by theme:


Return to index

First Aid and Emergencies


Prevention - Home Treatment - When to Call a Health Professional

Hypothermia occurs when your body temperature drops below normal. It develops when your body loses heat faster than heat can be produced by metabolism, muscle contractions, and shivering.

Early symptoms indicating mild to moderate hypothermia include:

  • Shivering

  • Cold, pale skin

  • Apathy (listlessness)

  • Impaired judgment

Later symptoms of severe hypothermia include:

  • Cold abdomen

  • Slow pulse and breathing

  • Weakness or drowsiness

  • Confusion

Shivering may stop if your body temperature drops below 35.5°C (96°F).

Hypothermia is an emergency. It can quickly lead to unconsciousness and death if the heat loss continues. Hypothermia can happen at temperatures of 7°C (45°F) or even higher in wet and windy weather. Frail and inactive people can develop hypothermia indoors if they are not dressed warmly.

Early recognition is very important in the treatment of hypothermia. Often a hiker or skier will lose heat to a critical degree before others notice anything is wrong. If someone starts to shiver violently, stumble, or respond incoherently to questions, suspect hypothermia and warm the person quickly.


Top of Page

Whenever you plan to be outdoors for several hours in cold weather, take the following precautions:

  • Dress warmly and wear windproof, waterproof clothing. Wear fabrics that remain warm even when wet, such as wool or polypropylene.

  • Wear a warm hat. An unprotected head loses a great deal of the body's total heat.

  • Head for shelter if you get wet or cold.

  • Eat well before going out and carry extra food.

  • Don't drink alcohol while in the cold. Alcohol makes your body lose heat faster.

  • Older or less active people can prevent indoor hypothermia by dressing warmly and keeping room temperatures above 18°C (65°F).

Home Treatment

Top of Page

The goal of home or "in-the-field" treatment is to stop additional heat loss and slowly rewarm the person. Warming 1° per hour is best.

  • For mild cases, get the person out of the cold and wind. Give the person dry or wool clothing to wear.

  • For moderate cases, remove cold, wet clothes first. Then warm the person with your own body heat by wrapping a blanket or sleeping bag around both of you.

  • Give warm liquids to drink and high-energy foods, such as candy, to eat. Do not give food or drink if the person is disoriented or unconscious. Do not give alcoholic beverages.

  • Rewarming the person in warm water can cause shock or heart attack. However, in emergency situations when help is not available and other Home Treatments are not working, you can use a warm water bath (37.8° to 40.6°C or 100° to 105°F) as a last resort.

When to Call a Health Professional

Top of Page

Call 911 or seek emergency care if the person seems confused or loses consciousness and remains unconscious.

Call your doctor:

  • If the victim is a child or an older adult. It's a good idea to call regardless of the severity of the symptoms.

  • If the person's body temperature does not return to normal after 4 hours of warming.


Top of Page