The Cold Facts on Hypothermia

We Canadians pride ourselves on our ability to cope with our severe winters. But we forget that the cold can and does kill. The dangers become all too clear when there is a disaster, and unprepared people become stranded or fall into cold water.

Hypothermia, sometimes called exposure, occurs when the body can no longer produce more heat than it is losing. The body's internal temperature then drops below 35 C or
95 ºF.

It's important for Canadians to know what leads to hypothermia. Wind, wet and cold are the key factors. Wind can chill the body as air moves over it. Water rapidly absorbs body heat; wet clothing is a common cause of hypothermia, and casualties in lakes and rivers are often due to hypothermia, not drowning. Cold air cools down the body - but it does not have to be frigid; hypothermia can happen at under 10 C, so it's a threat even with above-average winter temperatures.

Precautions Anyone can Take

The Canada Safety Council recommends preparing yourself against hypothermia if you are working outside or taking part in outdoor recreational activities:

  • Wear a warm hat. Most body heat is lost through the head.
  • Wear layered clothing. Proper layers will allow warm air to stay trapped but do not trap perspiration next to the skin.
  • Protect your feet and hands. Wear loose waterproof boots. If the boots have felt liners, carry an extra pair to replace damp ones. Mittens warm the hands more effectively than gloves. Carry an extra pair of these too.
  • Prevent dehydration and exhaustion, which can lead to hypothermia. Drink plenty of non-alcoholic fluids. Pace yourself when doing vigorous activity.
  • Stay fit through good physical conditioning and good nutrition. People who are fit are less susceptible to hypothermia. And don't let yourself become weakened through fatigue.
  • Try to stay in a heated environment, but not so hot as to cause excessive sweating. You risk hypothermia when you seek to cool down by leaving a hot environment for a cool one.
  • Eat high energy food, such as nuts and raisins.
  • Avoid alcohol, coffee, tea and tobacco. They can cause heat loss.
  • If you are traveling (on the road or in the wilderness) carry emergency supplies.

Sudden heart attacks increase during a cold snap. Cold air can cause blood pressure to go up, especially when skin is exposed. Shivering is a serious warning sign to seek a warmer, sheltered place.

Beware of the Symptoms

Initial Signs (Mild Hypothermia)

  • Bouts of shivering
  • Grogginess and muddled thinking
  • Breathing and pulse are normal

Danger Signs of Worsening Hypothermia (Moderate Hypothermia)

  • Violent shivering or shivering stops
  • Inability to think and pay attention
  • Slow, shallow breathing
  • Slow, weak pulse

Signs of Severe Hypothermia

  • Shivering has stopped
  • Unconsciousness
  • Little or no breathing
  • Weak, irregular or non-existent pulse

What to do if you Suspect Hypothermia

If you suspect hypothermia, take measures to prevent further heat loss and get medical help as quickly as possible. Continue the warming efforts even if there is little or no pulse or heartbeat. Severe hypothermia can be mistaken for death.

Move the casualty to a dry, warm location if possible, or provide protection from the wind. Keep the person in a horizontal position. If you can't replace wet clothes with dry ones, cover the wet clothes with warm dry clothing or blankets, and place something warm and dry under the casualty. If the person is conscious, supply a warm drink, but avoid alcohol and caffeine.

Knowing first aid is a tremendous help. But most deaths from hypothermia can be prevented if you use common sense.

Wear Layers to Keep Warm

Inadequate clothing lets the warmed air around the body escape. Proper clothing and protection trap the warm air around the body. The key is to keep warm and dry.

The first layer lets the skin breathe. Underwear, socks and glove liners of polypropylene or knitted silk lets perspiration escape from next to the skin. The second layer absorbs perspiration without allowing heat to escape. Wool is ideal because it stays warm even when wet. It also comes in many thicknesses. The third layer traps heat in, and keeps water or dampness out. A quilted coat filled with down or a lightweight microfibre is ideal. If it’s not waterproof, wear a water- resistant shell or windbreaker.

Shoveling All That Snow

Along with good skiing and tobogganing comes lots of snow. Unfortunately, it falls in the driveway as well as on the trails and slopes.

Always wear a hat and mittens when shoveling. If you have blood pressure problems, cover as much of your face as possible while outside in cold weather and don't over-exert yourself. Shoveling snow is of particular concern for middle-aged men with hypertension or high blood pressure.

Using a snow blower to clear your walk or driveway can be much easier than working with an old-fashioned shovel. But using modern equipment still demands old-fashioned common sense.