Hypothermia

1 What is Hypothermia?

Hypothermia a condition characterized by rapid heat loss from your body that exceeds the amount your body can produce. The heat loss is so rapid that it can lead to dangerously low body temperature.

Hypothermia is a medical emergency and requires immediate medical attention. Normal temperature of your body is around 98.6 F (37 C).

Hypothermia is said to occur when your body temperature drops below 95 F (35 C). Quick drop in body temperature disturbs normal functioning of your vital organs like heart and brain. Lack of immediate treatment can lead to heart failure, respiratory failure and ultimately death. Most common cause of hypothermia is an exposure to cold weather for longer period or contact with freezing water. Primary treatment aims to warm your body back to normal as soon as possible. 

2 Symptoms

Signs and symptoms of hypothermia may vary depending on its type.

As the body temperature starts to drop, your body induces shivering as an automatic defense mechanism against cold temperature. At this stage you are experiencing a mild hypothermia which can be indicated by following signs and symptoms:

  • Shivering
  • Dizziness
  • Hunger
  • Nausea
  • Faster breathing
  • Trouble speaking
  • Slight confusion
  • Lack of coordination
  • Fatigue
  • Increased heart rate

If left untreated, the condition can progress to moderate to severe hypothermia. You may not be able to judge your situation as the signs of hypothermia develop gradually. The signs and symptoms of moderate to severe hypothermia include:

  • Shivering, which might stop as hypothermia worsens
  • Uncoordinated movements
  • Slurred speech or mumbling
  • Drowsiness
  • lack of self-awareness
  • loss of consciousness
  • Weak pulse
  • Slow and shallow breathing
  • Confusion and problems with decision making, confusion leads to risk taking behavior

Typical signs of hypothermia in an infant are as follows:

  • Bright red, cold skin
  • Lack of energy
  • A weak cry

Infants and elderly people are more likely to lose body heat faster as compared to adults. Exposure to extremely cold temperature is not a necessary cause for hypothermia, prolonged exposure to low indoor temperatures usually due to poorly heating system can also be the culprit.

When to see a Doctor

As immediate response is required, it is better to call 911 or your local emergency number to take the suspected person to hospital. You may follow these tips to ensure better care for the victim:

  • Take the person inside a home slowly. Rapid movements can cause irregular heartbeats.
  • Remove the wet clothes and cover the person in layers of blankets.
  • Try to make him warm with any sources of heat.
  • Wait for emergency help to arrive.
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3 Causes

Most common cause of hypothermia is exposure to cold-weather conditions or cold water. Hypothermia occurs when your body temperature drops below 35 C. When you are exposed to any environment colder than your body and if you are not wearing warm clothes, you may develop hypothermia.

Followings are some specific conditions which may lead you to hypothermic state:

  • Not wearing warm clothes to suit with weather conditions
  • Staying out in the cold for long period
  • Wearing wet clothes for long time and unable to move to a warm, dry location
  • Accidental falls in cold water
  • Inadequate heating facilities at home, especially for elderly and infants
  • Cold air conditioning, especially for elderly and infants

Mechanism of heat loss from your body:

  • Radiated heat: Your body may radiate heat to surroundings from unprotected surfaces of your body.
  • Direct contact: When in direct contact with something very cold such as cold water or the cold ground, heat is conducted away from your body. Body heat is taken off by cold water much faster than cold air.
  • Wind: Wind is an important factor that can cause heat loss from your body. Colder the wind, rapid is the heat loss. A cold wind can blow away a thin layer of warm air from the surface of your skin causing loss of heat from your body.

4 Making a Diagnosis

Diagnosis of hypothermia is usually based on the signs and symptoms exhibited by the suspect.

Severity of the cases can be confirmed using blood test. Elderly person exposed to lower temperature for long time may show signs of confusion, lack of coordination and speech problems. Hypothermia in such cases may be confirmed by measuring body temperature with a rectal thermometer.

5 Treatment

A victim of hypothermia requires immediate medical attention. Here are some hypothermia treatment guidelines to follow:

First-aid care

  • Limit movements of the suspected person.
  • Make sure not to massage or rub the person as it may trigger cardiac arrest due to excessive, vigorous and jarring movements of body parts.
  • Try to move him gently to the warmer place.
  • Remove wet clothes if any. If removing is not possible, you may cut them off.
  • Wrap the victim with layers of blankets or coats from head to toe only sparing the face.
  • Don’t let the person have a direct contact with cold ground or any other surfaces.
  • If the victim is conscious, you may feed him with sweet, nonalcoholic and non-caffeinated warm beverage.
  • Monitor breathing: In worst cases, the person may become unconscious without any signs of a pulse or breathing. If the person is not breathing or has a shallow breathe, start cardiopulmonary resuscitation (CPR) immediately, if you know how.
  • Try to make the person as warm as possible. Skin to skin contact to share body heat is a good way. Make sure both of you are covered in blanket. First-aid warm compress (a plastic fluid-filled bag that warms up when squeezed) can be used too. Apply a compress only to the neck, chest wall or groin. Avoid applying it to the arms or legs as the process forces cold blood back toward the heart, lungs and brain, causing the core body temperature to drop further making the condition ever worse and fatal. Applying direct heat using hot water, heating pad or lamp is also not recommended as extreme heat can damage the skin as well as cause irregular heartbeats.

Medical treatment

In order to raise the body temperature, your doctor may follow different methods which may differ based on severity of hypothermia. Some of the methods are as follows:

  • Blood rewarming: This process involves drawing the blood, warming it and recirculating it using instruments like hemodialysis machine and heart bypass machines.
  • Warm intravenous fluids: A warm intravenous solution of salt water when injected into a vein can elevate the body temperature.
  • Airway rewarming: Humidified oxygen may be administered with a mask or nasal tube to raise the body temperature.
  • Irrigation: A warm saltwater might be useful to warm body parts like area around the lungs (pleura) or the abdominal cavity (peritoneal cavity).

6 Prevention

Prevention of hypothermia is better than cure. If you are planning to go outside into cold air, keep in mind the advice of COLD, which stands for cover, overexertion, layers, dry.

  • Cover: prevent heat loss from your head, face and neck by covering it with appropriate hat. Cover your hands with mittens.
  • Overexertion: Avoid overexertion to avoid sweating. Evaporation of sweat causes drop in body temperature. Do not wear wet clothes.
  • Layers: Wear loose fitting, layered, lightweight clothing during cold weather. Wear outer clothing made of tightly woven, water-repellent material for protection against wind. Wool, silk or polypropylene are materials of choice for inner layers to hold body heat better than cotton.
  • Dry: Try to keep yourself dry especially your hands and feet. Remove wet clothing as soon as possible.

Some tips to avoid Hypothermia include:

  • Take special care of infants and children. Keep them dressed in one more layer than an adult. Do not allow children to stay outdoor unless necessary. Keep babies in a warm room.
  • Follow winter car safety. While travelling in bad weather, inform someone close about your destination and estimated time of arrival.
  • Keep emergency supplies in your car which may include blankets, matches, candles, drinking water, a first-aid kit, dry or canned food, a can opener, tow rope, booster cables, compass, and a bag of sand or kitty litter, cellphone, etc. When stranded, put everything you need in the car with you, stay together, cluster around as near as possible and stay covered.
  • Keep your car warm by running it for 10 minutes every hour.
  • Keep a window slightly open and make sure that the exhaust pipe is not covered with snow while the engine is running.
  • Avoid drinking alcohol to avoid alcohol related risk of hypothermia in cases if you are going for boating in cold weather night.
  • Avoid long time exposure to cool water. Follow these tips to increase your survival time in cold water if you accidentally fall in:
  • Wear a life jacket. It helps you to float, save the energy and keeps you insulated for extra period. Try to hang on until help arrives.
  • Do not try to swim unless a safety is close to you. However, if possible, try to get out of the water by climbing onto a capsized boat or grabbing onto a floating object.
  • Stay in a position known as the heat escape lessening position (HELP) that minimizes heat loss. Try to hold your knees to your chest to protect the trunk. If your life jacket turns your face down in this position, bind your legs together and keep your arms to your sides and your head back.
  • Group up with others if others have fallen in cold water along with you. Stay in a circle facing each other to avoid heat loss. It is not advised to take off any clothing until you get out of the water. Body clothes keep you insulated. Try to keep your head covered all the time. Buckle, button and zip up your clothes.
  • Community outreach programs and social support services can be of great help for people who are at risk of hypothermia which include infants, older adults, people who have mental or physical problems or people who are homeless When someone is at risk, it is wise of you to contact your local public health office for available services such as assistance for paying heating bills, check-in services to see if you and your home are warm enough during cold weather. In case of emergency, go to homeless shelters, community warming centers, safe and warm daytime locations during cold weather.

7 Risks and Complications

There are several risks and complications associated with hypothermia.

Risks

  • Older age: Temperature sensitivity of human body depletes along with the increasing age. Elderly people are more susceptible to develop hypothermia because of this reason. Further, they are likely to possess a medical condition that may impair normal temperature regulation of the body. Due to poor mobility strength, some may not be able to move to dry place or even cannot communicate to do so.
  • Very young age: Children have a larger surface area-to-weight ratio than adults. Thus, they lose heat more rapidly than adults. Further, children do not care about cold as they are often busy playing. Infants are even more susceptible to hypothermia as they have underdeveloped and less efficient mechanisms for heat generation.
  • Mental problems: People with a mental illness, dementia or conditions that interfere with judgment may lack the sense of appropriate clothing during cold weather. Such people often go out in such weather and have high chances of getting stranded and becoming hypothermic.
  • Alcohol and drug use: Alcohol dilates your veins and causes rapid heat loss from the surface of your skin. A drunk person lack natural shivering response which may worsen the scenario. In addition, use of alcohol or recreational drugs interfere with your judgment. An intoxicated person can get stranded and pass out in cold weather and is likely to develop hypothermia.
  • Certain medical conditions: Hypothyroidism, malnutrition, anorexia, stroke, severe arthritis, Parkinson's disease, trauma, spinal cord injuries, burns, disorders that affect sensation in your extremities (for example, nerve damage in the feet of diabetics), dehydration, and any condition that restricts normal blood flow can affect body temperature regulation mechanisms.
  • Medications: Antidepressants, antipsychotics, narcotic pain relievers and sedatives can alter the mechanism of normal body temperature regulation.

Complications

People who develop hypothermia because of exposure to cold weather or cold water are also at risk of developing other cold-related injuries such as frostbite and gangrene.

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