Topic Overview

What is hypothermia?

Hypothermia occurs when the body gets cold and loses heat faster than the body can make it.

A rectal temperature is considered the most accurate body temperature. A normal rectal body temperature ranges from 97.5°F (36.4°C) to 99.6°F (37.6°C), and for most people it is 98.6°F (37°C). For information on how to take an accurate temperature, see the topic Body Temperature.

Sometimes a normal, healthy adult has a low body temperature, such as 96°F (36°C). If the person with the low body temperature is not ill, does not have any other problems, and is not an infant or an older adult, then evaluation usually is not needed.

What can cause hypothermia?

Hypothermia can occur when you are exposed to cold air, water, wind, or rain.

Your body temperature can drop to a low level at temperatures of 50°F (10°C) or higher in wet and windy weather, or if you are in 60°F (16°C) to 70°F (21°C) water. If you have mild hypothermia, home treatment may be enough to bring your body temperature back up to normal.

What are the symptoms?

Early symptoms include:

• Shivering.
• Cold, pale, or blue-gray skin.
• Lack of interest or concern (apathy).
• Poor judgment.
• Mild unsteadiness in balance or walking.
• Slurred speech.
• Numb hands and fingers and problems performing tasks.

Late symptoms include:

• The trunk of the body is cold to the touch.
• Muscles becoming stiff.
• Slow pulse.
• Breathing that is shallow and slower.
• Weakness or sleepiness.
• Confusion.
• Loss of consciousness.
• Shivering, which may stop if body temperature drops below 90°F (32°C).

What can happen from hypothermia?

Hypothermia is an emergency condition and can quickly lead to unconsciousness and death if heat loss continues. It is very important to know the symptoms of hypothermia and get treatment quickly. Often a hiker or skier's body temperature will drop really low before others notice that something is wrong. If someone begins to shiver violently, stumble, or can't respond to questions, it may be hypothermia and you need to warm him or her quickly. For information about when to seek medical care, see the topic Cold Temperature Exposure.

Who is at risk for hypothermia?

Anyone can get hypothermia.

Most healthy people with mild to moderate hypothermia recover completely without permanent injury. Recovery is harder for babies and older, ill, or inactive adults. Hypothermia can occur indoors, especially in babies and older or ill adults that are not dressed warmly enough.

How is it treated?

Medical treatment for hypothermia depends on the severity of the hypothermia. Treatment of mild hypothermia includes getting out of the cold or wet environment, using warm blankets, heaters, and hot water bottles.

Moderate to severe hypothermia generally is treated in the hospital, where doctors can use special techniques to warm the core body temperature.