Hypothermia is a medical emergency that occurs when your body loses heat faster than it can produce heat, causing a dangerously low body temperature. Normal body temperature is around 98.6 F (37 C). Hypothermia (hi-po-THUR-me-uh) occurs as your body temperature passes below 95 F (35 C).
When your body temperature drops, your heart, nervous system and other organs can't work correctly. Left untreated, hypothermia can eventually lead to complete failure of your heart and respiratory system and to death.
Hypothermia is most often caused by exposure to cold weather or immersion in a cold body of water. Primary treatments for hypothermia are methods to warm the body back to a normal temperature.
Shivering is your body's automatic defense against cold temperature — an attempt to warm itself. Constant shivering is a key sign of hypothermia. Signs and symptoms of moderate to severe hypothermia include:
A person with hypothermia usually isn't aware of his or her condition, because the symptoms often begin gradually and because the confused thinking associated with hypothermia prevents self-awareness.
Hypothermia not necessarily related to the outdoors
Symptoms of mild hypothermia not related to extreme cold exposure are nearly identical to those of more severe hypothermia, but may be much less obvious. Signs and symptoms of mild hypothermia may include:
Hypothermia in infants
When to see a doctor
Hypothermia occurs when your body loses heat faster than it produces it. The most common causes of hypothermia are exposure to cold-weather conditions or cold water. But prolonged exposure to any environment colder than your body can lead to hypothermia if you aren't dressed appropriately or can't control the conditions. Specific conditions leading to hypothermia can include:
How your body loses heat
A number of factors can increase the risk of developing hypothermia:
People who develop hypothermia because of exposure to cold weather or cold water are also vulnerable to other cold-related injuries, including:
Tests and diagnosis
The diagnosis of hypothermia is usually apparent based on a person's physical signs and the conditions in which the person with hypothermia became ill or was found.
A diagnosis may not be readily apparent, however, if the symptoms are mild, as when an older person who is indoors has symptoms such as confusion, lack of coordination and speech problems. In such cases, an exam may include a temperature reading with a rectal thermometer that reads low temperatures.
Treatments and drugs
Seek immediate medical attention for anyone who appears to have hypothermia. Until medical help is available, follow these hypothermia treatment guidelines.
Staying warm in cold weather
Keeping children safe outdoors
Winter car safety
Don't drink alcohol:
Help for at-risk people
Last Updated: 2011-06-08
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