Hypothermia

What is Hypothermia

Hypothermia is a drop in body temperature to 95°F (35°C) or lower. The average body temperature is between 97°F (36.1°C) and 99°F (37.2°C). Hypothermia is life-threatening because the body’s organs cannot work properly when the body’s temperature is too low.

6 Interesting Facts of Hypothermia

1. Body temperature 35°C or lower
2. As with nitrogen narcosis, divers with moderate hypothermia (28°C-32°C) can experience confusion and/or altered mental status
   • Unconsciousness occurs with severe hypothermia (less than 28°C)
3. Unlike nitrogen narcosis, moderate hypothermia while diving would be preceded by mild hypothermia (32°C-35°C) with noticeable shivering and hyperventilation
4. Would not occur in a hyperbaric chamber setting
5. Hypothermia is also risk factor for developing nitrogen narcosis; therefore, both conditions may be present
6. Differentiated on basis of diving conditions (low water temperature), shivering, and patient’s body temperature after surfacing

What are the causes?

This condition may be caused by:

• Being in cold weather or a cool room without being dressed warmly enough.
• Getting wet, such as from rain or from falling into cool water.
• Medical conditions that affect body temperature, such as hypothyroidism, diabetes, or Parkinson disease.
• Medicines that affect the body’s ability to control temperature.

What increases the risk?

This condition is more likely to develop in:

• People who are outside for long periods of time, such as hikers, hunters, or homeless people.
• People who use drugs.
• People who have difficulty moving around (impaired mobility).
• Babies.
• Elderly adults.
• People who have a medical condition that affects body temperature.
• People who take medicine that affects the body’s ability to control temperature.
• People who drink too much alcohol or who drink it too often.

What are the symptoms?

At first, symptoms of hypothermia may include:

• Shivering. Shivering may happen early in hypothermia and may stop as the condition gets worse. Hypothermia does not always cause shivering.
• Slow thinking, speech, and response time.
• Sleepiness.
• Confusion.
• Pale skin.
• Puffy or swollen face.
• Numbness.
• In infants, skin that is red and cold.

As hypothermia gets worse, the following symptoms may develop:

• Uncoordinated movements.
• Slow, shallow breathing.
• Slow, weak pulse.
• Loss of consciousness.

How is this diagnosed?

This condition is diagnosed by taking your temperature. You may also have tests, such as:

• Blood tests.
• Glucose test.
• Urine tests.
• Liver tests.
• Heart tests, such as an electrocardiogram (ECG).

How is this treated?

It is important to seek treatment as soon as possible. Hypothermia is an emergency that needs to be treated in a hospital. Treatment for hypothermia may include:

• Receiving IV fluids.
• Receiving warm, humidified oxygen through nasal tubing (nasal cannula), an oxygen mask, or a breathing tube.
• Rewarming the blood by removing it, passing it through a hemodialysis machine, and returning it to the body at gradually increasing temperatures.
• Receiving a warm solution through a small tube that goes into the stomach, bladder, or intestine (cavity lavage).

How is this prevented?

• If you have an increased risk of developing hypothermia, keep your home at 68°F (20°C) or warmer.
• Stay alert for dangerous weather situations and plan accordingly. Keep warm items in your house and car and observe safety precautions from government or weather officials.
• Get out of cold water right away, and replace wet clothing with dry clothing as soon as possible.
• Do not ignore signs that you are cold, such as shivering, cold feet and hands, and numbness.
• If you know you will be in a cold environment:
  • Wear layers of clothing.
  • Do not drink alcohol. Alcohol causes your blood vessels to get larger (dilate) which makes you lose body heat.
  • Cover up with blankets.
  • Wear a waterproof jacket if you are outside in the rain or snow.

What are some ways to prevent hypothermia?

• Do not underestimate the cold. Most cases of hypothermia develop at 30–50°F (1–10°C).
• Do not ignore shivering. Persistent or violent shivering is a warning that your temperature is dropping and that you may be on the edge of getting hypothermia.
• Dress appropriately for the cold:
  • Make sure your face, ears, and neck are covered before going into cold weather. Parkas with hoods that extend several inches beyond your face are great in protecting against wind and blowing snow.
  • Wear a pair of cotton socks under a pair of wool socks to increase insulation and to take the sweat away from your feet.
  • Wear layers. If you begin to sweat, take a layer off so that your clothing does not become wet.
• Stay dry. If any of your clothing gets wet, replace it right away. Your body loses heat more quickly if your clothes are wet.
• Stay out of the wind.
• Drink enough fluid to keep your urine clear or pale yellow.
• Do not skip meals.
• Do not drink alcohol if you are going to be outside in cold weather, if you are going boating, or before going to bed on cold nights. Alcohol causes your body to lose heat.

What are some ways to prevent hypothermia in water?

Water does not need to be extremely cold to cause hypothermia. Water at any temperature colder than your normal body temperature will cause you to lose heat. If you fall into cold water:

• Get out of the water right away. If you cannot get out of the water, get as much of yourself out as possible by climbing onto anything floating nearby, such as an overturned boat.
• Do not attempt to swim unless land, a boat, another person, or a life jacket is close by. Swimming uses up energy and may shorten survival time.
• Do not remove your clothing until you are safely out of the water and can get dry or warm. When in the water, buckle, button, and zip up your clothes. The layer of water between your clothing and your body will help insulate you and keep you warm.
• Hold your knees to your chest. The knee-to-chest position minimizes heat loss.
• If you have fallen into the water with other people, face each other, create a tight circle, and huddle together.

Remember to wear a life jacket if you plan to ride in any watercraft. A life jacket can keep you alive longer in cold water by helping you float without using energy and by providing insulation to reduce heat loss.

What are some ways to prevent hypothermia if you are stranded in your car?

Keep emergency supplies such as blankets, gloves, and a change of clothes in your car. If you get stranded in your car, cover yourself with the blankets or clothing. If there are others in the car with you, huddle together. Run the car for 10 minutes each hour to warm it up. Make sure a window is slightly open and the exhaust pipe is not covered with snow while the engine is running.

What are some ways to prevent hypothermia in children?

Children lose heat faster than adults do. Accidental hypothermia can occur even with temperatures of 60–65°F (15.6–18.3°C), particularly among infants.

• Infants less than one year of age should never sleep in a cold room. They should be provided with warm clothing and a wearable blanket to prevent loss of body heat.
• To help prevent hypothermia when children are outside in the winter:
  • Dress infants and young children in one more layer than an adult would wear in the same conditions.
  • Limit the amount of time children spend outside in the cold.
  • Have children come inside often to warm up.

Get help right away if:

• You develop symptoms of hypothermia.
• Hypothermia symptoms get worse or do not get better.