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What is hypothermia?
Hypothermia is a medical condition. It occurs when you are exposed to bitter cold for a long time. Normal body temperature is 37°C (98.6°F). You have hypothermia if your body temperature drops below 35°C (95°F). Hypothermia also can occur in temperatures above 4°C (40°F). This is usually due to a person being wet, sweaty, or trapped in cold water. It is dangerous and life threatening. Most people don’t know they have it until it’s too late. If left untreated, hypothermia can cause a heart attack, liver damage, kidney failure, or death.
Hypothermia is different from frostbite. You can have frostbite by itself or with hypothermia. It depends on the type. Frostbite is an injury you get when a part of your body freezes. Common locations of frostbite are your nose, ears, fingers, and toes. With frostbite, your body parts can be numb, stiff, and/or white or grayish-yellow. The effects can be long-term for severe injuries. It may require amputation.
Symptoms of hypothermia
Symptoms are difficult to spot in babies and older people. Warning signs include:
- Shivering, fumbling hands, and/or decreased movement
- Unclear speech
- Sudden exhaustion or low energy
- Sudden confusion; unable to think clearly
- Cold, red, and/or raw skin. Skin may turn blue in later stage.
- Decreased breathing or heart rate.
What causes hypothermia?
Hypothermia is caused by a drop in your body temperature. When your temperature drops, your body uses stored energy to stay warm. Hypothermia begins when the stored energy is used up. Your body can no longer produce heat. There are a few types of this condition with varying causes.
- Acute hypothermia. This occurs when your body temperature drops suddenly. This can happen if you fall into cold water. It also can happen if you are wet and in the cold. Hikers, hunters, and people who are homeless are at risk. People who are stranded outside in the cold for too long are at risk.
- Chronic hypothermia. This occurs when your body temperature drops over a period of time. Elderly people and babies have a harder time controlling their body temperature. They are at risk of getting hypothermia over time. People of low incomes who don’t have access to heat or proper clothing are at risk.
- Exhaustion hypothermia. This occurs when your body temperature drops because it is too tired to produce heat. People who are sick, have certain health conditions, or have substance use disorders are at risk.
- Perioperative hypothermia. This occurs when your body temperature drops after surgery in a hospital. It can be hard to maintain heat after receiving anesthesia.
How is hypothermia diagnosed?
If you suspect a person has hypothermia, take their temperature. A reading of less than 35°C (95°F) means they could have hypothermia. You should get medical care immediately. A healthcare provider will perform a physical exam. They will want to know the person’s lifestyle to determine what may have caused or contributed to the hypothermia. Additional tests could include:
- Temperature test: The healthcare provider will test the ear or rectum (bottom). This provides the most accurate reading.
- Electrocardiography (EKG): This test uses electric waves to look at your heartbeat. This will determine if it’s normal or not.
- Chest X-ray: This test uses radiation to look your chest and surrounding organs. Your healthcare provider is looking for disease or injuries.
- Blood test: This test checks for substances in your blood.
- Computed tomography scan (CT scan): This test uses X-rays to check for internal injuries or other health problems.
- Magnetic Resonance Imaging (MRI): This test uses radio waves to check for other injuries, such as head trauma.
Can hypothermia be prevented or avoided?
You can prevent or avoid most cases of hypothermia. To reduce your risk:
- Prepare for cold weather. Warm clothing and hats retain heat. Wear layers to prepare for changing conditions.
- Proper winter clothing includes:
- Mittens (not gloves)
- Raincoat and windbreaker
- Two pairs of socks (not cotton)
- Scarf and hat (that covers the ears)
- If you get wet, change your clothes immediately. Look for a warm, indoor area.
- Keep extra items in your car when traveling. This includes clothes, food, water, and blankets. If you get stranded in your car, call or signal for help right away. Stay in your car. Run the car heater for 10 minutes per hour to conserve gas. Make sure your car’s exhaust pipe is not blocked by snow. This can cause carbon monoxide poisoning.
- Do not eat snow or drink alcohol. This lowers your body temperatures.
- In cold temperatures, stay active to produce body heat and store energy.
- Care for babies. Check in on elderly people. Make sure they are warm, dry, clothed, and fed.
Contact a healthcare provider immediately if you suspect you or someone else has hypothermia. Additionally:
- Move the person into a warm place as soon as possible.
- Give the person warm clothing. If their current clothes are wet, remove them.
- Cover the person with blankets or towels. Use an electric blanket or heating pad, if possible.
- Skin-to-skin contact with another person helps increase body temperature.
- Have the person drink warm liquids but avoid alcohol and caffeine.
- If the person is not breathing, begin CPR right away. Stay with the person until help arrives.
A hospital may provide other treatment. One example is injecting warm fluids and/or oxygen into the body. Another example is to flow the person’s blood through an external device to warm it up.
Living with hypothermia
Hypothermia can be cured with little to no lasting effects. Severe hypothermia may require ongoing treatment. Medical conditions that caused the hypothermia will need to be treated.