Extreme Cold

Hypothermia, a condition that occurs when the body temperature falls below the normal range, is caused by a low surrounding temperature and can lead to death. Freezing temperatures cause frostbite, whereby ice forms in the body tissue and destroys it. The risk of frostbite is increased by windy conditions.

Causes of hypothermia

Hypothermia (low temperature) occurs when the body temperature falls below the normal range, and can lead to death. The average temperature of a healthy adult is 36-38°C (96.8-100.4°F). Hypothermia occurs when the body's core temperature falls below 35°C (95°F). Survival is unlikely, but not unheard of, below 26°C (79°F).

There are a number of factors that heighten the risk of becoming hypothermic. These include:

• Age

The elderly are at greater risk from hypothermia: low mobility combined with poor circulation, a reduced sensitivity to the cold and a greater potential for slips and falls means that an elderly person may develop hypothermia in temperatures that a healthy younger adult could tolerate.

The very young are also at an increased risk as their mechanisms for controlling their own body temperature are poorly developed. They may look healthy but their skin will feel cold and their behaviour may be abnormally, quiet or listless.

• Exposure to wind or rain
• Immersion in cold water
• Lack of food
• Alcohol and drugs

Signs and symptoms of hypothermia

Early signs:

• Shivering
• Pale, cold skin
• Cold environment
• Presence of an increased risk factor as listed left

As the condition gets worse:

• No shivering, even though the person is cold
• Increasing drowsiness
• Irrational behaviour and confusion
• Slow, shallow breathing
• Slow, weak pulse

Treatment

If the person is unconscious

Open the airway and check for breathing. Be prepared to resuscitate if necessary. Hypothermia slows the body's functions down before stopping the heart, and it is therefore not uncommon to hear of people with hypothermia being successfully resuscitated some time after the heart has stopped.

If the person is conscious

1. Improve the surroundings. If the person is outdoors, bring them in or take them to shelter. If the person is indoors, warm the room but do not overheat(25°C/ 77°F).
2. Replace wet clothes with dry warm clothing if possible.
3. A healthy adult may be best rewarmed by soaking in a warm bath of 40°F (104°F). Do not use this technique on an elderly person or a child.
4. Wrap the person up and give high energy foods and warm drinks. Remember that heat is lost through the extremities so cover the head, hands and feet.
5. Check for other conditions or injuries. The confusion caused by hypothermia may mask other signs and symptoms. If there is no improvement, or the level of consciousness deteriorates, seek medical advice. For young children and the elderly, who are particularly vulnerable, always seek medical attention if you suspect hypothermia. Rewarm them slowly.

Frostbite

Frostbite occurs in freezing conditions and is the freezing of body tissue at the extremities, most commonly the fingers, toes and earlobes. If it is not treated early enough it can lead to gangrene and to amputation. Frostbitten skin is highly susceptible to infection.

Signs and symptoms of frostbite

• Freezing environment

Early signs

• Pins and needles
• Pale skin

As the condition gets worse

• Numbness
• Hardening of the skin
• Skin colour changes to white, through blue and finally black

When thawed, the injured part is extremely painful and there may be blistering of the skin.

First Aid Treatment

1. Remove tight items such as rings and watches that may further damage circulation. Warm the injured part slowly by holding it.
2. Get the person to shelter. Do not attempt to thaw the injured part if it is liable to be re-exposed to cold, as this will do more damage.
3. Handle the injured part carefully as the tissue is very fragile and may be easily damaged. Do not apply direct heat to the injured part, rub it or allow the injured person to apply pressure to it (for example, do not let the person walk if the toes are affected). Place the injured part in warm water if available. Otherwise continue warming with your hand.
4. Pat dry and then cover with a light gauze bandage. Remember that the injured part will be exceptionally painful.
5. Raise the injured part to help alleviate pain and swelling and allow the injured person to take paracetamol if able to.
6. Watch for hypothermia and treat as appropriate.
7. Seek medical attention, particularly if the site of the freezing does not regain a healthy colour or is black.