Low Body Temperature (Hypothermia)

Medically Reviewed By William C. Lloyd III, MD, FACS
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What is low body temperature (hypothermia)?

Hypothermia is an abnormally low body temperature. Normal body temperature should be somewhere close to 98.6° F. Hypothermia occurs when body temperature drops to 95 °F. It is the result of the body losing heat faster than it can make it. This can happen quickly in very cold temperatures. It can also happen with prolonged exposure to cool or cold temperatures as the body uses up all its stored energy.

Hypothermia is dangerous because it causes vital organs to stop working the way they should. It can lead to heart attack, kidney failure, and liver damage. It also affects the brain making it difficult to think clearly and move. As a result, someone suffering from hypothermia may not realize it. They may even engage in irrational or risky behaviors, such as removing clothing. If they do understand what’s going on, they may have trouble helping themselves or doing anything about their condition.

Hypothermia is a medical emergency. Symptoms tend to develop gradually, so they can be difficult to spot in the early stages. Left untreated, hypothermia can cause death very quickly. Seek immediate medical care (call 911) if you suspect hypothermia due to symptoms including:

Symptoms of hypothermia in babies include low energy and bright red, cold skin.

While you are waiting for help, take the following first aid steps for hypothermia:

  • Move the person inside, somewhere warm, or to a shelter of any kind out of the wind. If you must remain outside or in a shelter, insulate the person from the ground with anything you can layer under them.

  • Remove wet clothing as gently as possible.

  • Cover the person with anything available, such as a dry sheet or jacket. Ideally, an electric blanket is the best option. Hot water bottles and chemical heat packs will also work. Just be sure to put something, such as a towel or shirt, between these heat sources and their skin to protect it. If nothing else is available, use skin-to-skin contact with a warm body.

  • Concentrate on warming the head, neck and trunk of the body gradually. Warming or rubbing the limbs before the core is warm can add further stress to the heart and lungs.

  • Help conscious people drink warm, and ideally sweet, liquids without caffeine or alcohol.

  • Check unconscious people for signs of life including breathing and heartbeat. If these signs are absent, begin CPR (cardiopulmonary resuscitation).

What other symptoms might occur with low temperature (hypothermia)?

Frostbite is another type of cold injury that can happen with hypothermia. It is the result of cold freezing a body part. The frozen body part becomes numb and loses color. It most commonly affects the ears, nose, cheeks, fingers and toes. It can lead to permanent damage and even amputation.

Early signs of frostbite danger include pain and redness of the skin. Signs and symptoms of frostbite include:

  • Firm or waxy skin

  • Numbness

  • White, grayish or yellowish skin

Frostbite is also a medical emergency. Seek immediate medical care (call 911) for signs of frostbite and follow the same first aid steps as hypothermia. Concentrate on gradually warming the frostbitten area without massaging it. Avoid walking on frostbitten feet, as this increases damage to the area.

What causes low temperature (hypothermia)?

Hypothermia happens when your body loses heat more quickly than it can make it. The body can lose heat in four ways:

  • Conduction: The body transfers heat to matter. Conduction can happen when you lay on the ground. Your body will transfer heat to the earth. Conduction happens faster in water, which conducts heat 25 times faster than air. Moisture and wetness speed up the conduction process and causes hypothermia more quickly.

  • Convection: The body loses heat to passing molecules. Wind is the main convection risk in hypothermia. Moving air will draw heat away from the body faster than calm air. This is why wind chills feel colder than the actual air temperature.

  • Evaporation: The body loses heat when liquid converts to gas. Your body’s normal way of cooling itself involves evaporation of sweat, which cools the skin. In cold or cool environments, sweat evaporation will increase heat loss. Sweating can also lead to dehydration, which contributes to hypothermia.

  • Radiation: The body loses heat to the environment. This is basic body heat loss to air that is colder than your body temperature. The greater the difference between your body temperature and the air temperature, the faster the loss occurs. Having exposed skin will also increase the rate of heat loss.

The most common cause of hypothermia is exposure to cold weather or cold water. However, it can also happen in cool temperatures if you do not have adequate clothing, are wet, or with prolonged exposure. This includes being in a house that is too cool.

Babies and older people are especially susceptible to hypothermia. Other risk factors include:

  • Alcohol and drug use, which can make you feel warm when you are in fact losing body heat

  • Certain medications, such as antidepressants and sedatives, which can interfere with your body’s temperature regulation

  • Fatigue

  • Medical conditions, such as hypothyroidism, diabetes, and nervous system diseases and injuries

  • Mental health problems and dementia

How is hypothermia treated?

Hypothermia is treated by warming your body and removing wet clothing. It is important to focus first on warming the central portion of the body; otherwise, blood vessels of the skin may dilate and your temperature may drop. Once your temperature starts to increase, your extremities can also be warmed. The person should be kept warm and dry, and medical attention should be sought as soon as possible. Seek immediate medical care (call 911) for signs and symptoms of hypothermia. 

Even if the hypothermia victim appears dead, the combination of cardiopulmonary resuscitation (CPR) and warming his or her body may result in successful resuscitation.

Common hypothermia treatments

The main goal of hypothermia treatment is to return the body to a normal temperature. This should be done carefully to avoid further injury, and extreme heat should be avoided. You can perform some treatments as part of first aid, but certain treatments require professional medical equipment and trained personnel, such as emergency medical technicians, nurses, and doctors.

Common treatments for hypothermia include:

  • Moving the person out of the cold

  • Placing warm saline in the stomach, colon or bladder

  • Providing cardiopulmonary resuscitation (CPR) if necessary

  • Providing warm intravenous fluids

  • Providing warm, humidified oxygen through a facemask or nasal tube

  • Providing warm, nonalcoholic beverages if the person is awake and alert

  • Removing wet clothing

  • Using skin-to-skin contact to warm the person

  • Warming the blood if equipment is available

  • Warming the torso, neck, head and groin first

  • Wrapping the victim in an electric blanket if possible

What are the potential complications of low temperature (hypothermia)?

With prompt treatment, people can recover from hypothermia without complications. When hypothermia is severe or prolonged, organ damage can occur. This includes problems with the brain, heart, kidneys and liver. Damage to these organs may require ongoing medical care. In addition, it is important to treat any underlying medical conditions that contributed to hypothermia.

You can take steps to protect yourself and prevent hypothermia including:

  • Adequately heat your home during cold weather 

  • Avoid overexertion in cold weather, which can result in sweating and wet clothing

  • Change out of wet clothing, including gloves, mittens, hats and socks, as soon as possible

  • Cover your skin including your hands and head

  • Wear layers of the right kind of material. A wicking layer under wool is the safest choice for cold weather. Cotton does not insulate as well as wool and can lead to hypothermia when it is wet.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Jun 22
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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