Hypothermia is a condition that occurs when your body temperature drops below 95°F (35°C). It may lead to life threatening complications if not treated immediately by healthcare professionals.

Your body’s normal temperature ranges between 96.8°F and 99.5°F (36.5°C and 37.5°C).

Hypothermia may occur when body temperature drops below this range. It’s most often caused by exposure to cold environments for prolonged periods.

Hypothermia is a particularly dangerous condition because it can affect your ability to think clearly, decreasing your likelihood of seeking medical help.

According to the National Library of Medicine, hypothermia causes up to 1,500 deaths each year in the United States. This includes 1 in 2 people with moderate to severe hypothermia who receive emergency medical treatment.

Keep reading to learn more about the symptoms, causes, and treatments for hypothermia.

What are the stages of hypothermia?

There are three stages of hypothermia, which have different ranges of core body temperatures:

  • Mild: 90°F to 95°F (32°C to 35°C)
  • Moderate: 82°F to 90°F (28°C to 32°C)
  • Severe: less than 82°F (28°C)

Symptoms, treatments, and outlooks may vary depending on the severity of hypothermia.

However, it’s important to get immediate medical attention if you suspect that you or someone you’re with has hypothermia, regardless of how severe it may be.

The most common symptoms of hypothermia may include:

Severe hypothermia

If you have severe hypothermia, you may also experience:

If you suspect that you or someone you’re with has hypothermia, get immediate medical attention.

Hypothermia occurs when your body loses more heat than it can generate, according to the Centers for Disease Control and Prevention (CDC).

Prolonged exposure to cold weather is the primary cause of hypothermia. Other causes may include:

  • staying in cold water for too long
  • having wet clothes in the cold
  • living in a cold house, especially for babies

When your body is exposed to prolonged cold, you may start to shiver and your basal metabolic rate (BMR) will increase. These are your body’s natural responses to generate more heat. Blood vessels in your hands and feet may also constrict (peripheral vasoconstriction) to prevent blood from cooling and returning to your organs.

However, when these bodily functions stop, your body temperature can drop quickly and significantly.

Researchers have identified several risk factors that may impact how your body generates heat or feels the cold, increasing your risk of hypothermia. These may include:

Hypothermia is a medical emergency that requires immediate medical attention. Call 911 as soon as possible if you suspect that you or someone you know has hypothermia.

The goal of hypothermia treatment is to increase body temperature to a normal range. The CDC recommends the affected person or their caregiver take the following steps while waiting for medical attention:

  • Get yourself or the person into a warm room or dry shelter.
  • Remove wet clothes, cutting them off if necessary to avoid moving the person.
  • Cover with dry blankets, including the head, chest, neck, and groin areas, but not the mouth.
  • If blankets aren’t available, use your body heat to warm the person up.
  • If the person is conscious, try to give them a warm, nonalcoholic beverage.

Monitor the individual’s breathing. If their breathing seems dangerously slow, or if they lose consciousness, perform CPR if you’re trained to do so.

While waiting for medical attention, it’s important to handle the affected person gently. Avoid excessive movements, as this may cause cardiac arrest.

Similarly, avoid using heating pads or lamps on the legs and arms. Applying a compress to these areas will push cold blood back toward the heart, lungs, and brain, which could be fatal.

Medical treatment

Severe hypothermia is treated in the hospital. Three common approaches may be used depending on the severity of your condition:

  • Passive external rewarming: This involves placing dry, warm blankets over the person with mild hypothermia to warm up the body temperature by up to 3.6°F (2°C) per hour.
  • Active external rewarming: This involves using external heat sources, such as a medical convective warming blanket system, for a person with moderate to severe hypothermia.
  • Active internal rewarming: Treatment for severe hypothermia may involve delivering warm humidified air to the airway, administering warm fluids intravenously, and washing body cavities and internal membranes with warm saline. In extreme cases, a machine may be used to pump blood out of the body, warm the blood, and then return it to circulation.

Immediate medical attention is crucial for preventing complications. The longer you wait, the more complications may arise from hypothermia.

A common complication of hypothermia is frostbite, which may lead to gangrene, limb loss, and amputation.

Other complications may include:

Preventive measures are key to avoiding hypothermia. The CDC recommends the following prevention tips:

  • dressing in dry, waterproof, and loose layers on cold days
  • covering all your body parts, including head, face, hands, neck, and ankles
  • taking care when sweating in cold temperatures
  • avoiding swimming in cold water for too long

Can you fully recover from hypothermia?

Most people with mild hypothermia will fully recover without any complications. However, you may experience complications if you have severe hypothermia or risk factors, such as underlying health conditions.

How long can hypothermia last?

Hypothermia doesn’t resolve on its own, so there’s no definite duration. It could last until warming methods are introduced. There’s also no defined period between the onset of hypothermia and cardiac arrest, so early treatment is crucial to prevent complications.

What happens if you warm up too quickly after hypothermia?

Warming up too quickly after hypothermia can significantly increase your risk of cardiac arrest. Other complications of rewarming may include inflammation, arrhythmias, severe infections, and blood clots, among others.

Hypothermia is an emergency health condition that happens when your body loses more heat than it can generate. It’s usually caused by prolonged exposure to cold environments.

Call 911 or your local emergency services if you or someone you know experiences hypothermia to help reduce your risk of life threatening complications.