Few paddlers die of hypothermia in Australia; however, there are a number of instances of paddlers suffering from the early stages of this dangerous condition. Many have experienced extreme cold, uncontrollable shivering and loss of concentration, while canoeing in the winter. Others who have capsized several times on a long day trip, have developed severe symptoms and become a danger to themselves and other paddlers.
So what is Hypothermia?
Hypothermia is the cooling of the body to such a point that it can no longer maintain a constant temperature, and the inner body core temperature falls below 35 degrees centigrade. Our bodies operate most efficiently within a narrow temperature range 36 - 37 degrees. When heat is taken away at a rate greater than heat produced in your body, you will become hypothermic. You are unlikely to know how much your temperature has fallen, but as the body becomes very cold, steps to prevent hypothermia are necessary. Take immediate and urgent steps to return body heat.
Prevention of Hypothermia
- Paddle water within your capability, as capsizes in cold water can quickly cause hypothermia
- Wear suitable clothing (eg wool, thermal wear, wet suit). Cotton is not recommended as it gives poor insulation, particularly when wet. Carry spare clothing in your boat. Try to keep clothing dry
- Avoid becoming exhausted. If you start to feel tired, stop for a rest, have a snack, warm up and then continue.
- Wear wind resistant clothing. If you are cold and wet, the wind increases the chill factor significantly.
Avoid wearing wet clothing for prolonged periods of time. Stop, dry off and change.
Eat sufficient energy food before and during the trip. The calories used for exercise also help to produce heat.
- Adequate water intake is extremely important to prevent dehydration, even in the cold. Dehydration will cause a 30% to 40% decrease in thermal control.
- Avoid prolonged immersion in cold water.
Early Stages of Hypothermia
- Goose bumps. Shivering
- Feeling intensely cold
- Skin becomes pale.
On a canoe trip, it is unlikely that the victim of hypothermia will want to stop for treatment willingly. They usually feel guilty about slowing the group down, especially if there is a long way to go. It will be up to the leader to address the situation before the paddler's condition becomes critical.
- In the early stages, the paddler should leave the cold river environment and shelter from the chilling effect of the wind or rain.
- Change into dry warm clothing and, in some cases, put on more clothing.
- Give the paddler warm sweet drinks (but not coffee or alcohol) and some high energy food. This may be enough to stabilise the paddler if the condition is mild.
- Warm the paddler slowly around a fire, but only in the early stages of hypothermia.
- Exercise such as walking will help warm the paddler. You may have to consider walking the paddler out to a safer environment. Do not let the paddler walk alone, preferably two people should go, as the cold may have clouded the paddler's thinking and judgement.
- If the weather conditions are bad, erect or find a sheltered environment and keep the paddler warm while someone goes for help.
Serious Stages of Hypothermia
- Lack of muscle co-ordination and slurred speech
- Uncontrollable shivering
- General comprehension of the situation is dulled and the patient may become irrational
- Pulse and respiration rate slows down.
Swift action is necessary at this stage as the patient is no longer able to generate body heat.
- Send someone for help as soon as possible and arrange IMMEDIATE TRANSPORT TO HOSPITAL
- Erect a shelter or find a sheltered environment.
- Remove wet clothing and replace with dry clothing.
- Lay the patient down, making sure the body is insulated from the ground.
- Cover the patient with more insulating material, eg survival blanket, jackets, warm clothes or warm buoyancy aids, that have been heated in front of the fire.<%4> Exchange them for others as they cool.
- Build a fire to keep other paddlers warm but DO NOT apply direct heat to limbs or extremities of the patient.
- DO NOT allow the patient to exercise.
- Give warm drinks only if the patient is conscious. DO NOT give coffee, as caffeine causes vasodilation which assists loss of heat.
- Concentrate on warming areas of high heat loss, eg armpits, sides, chest, head, neck, groin. This is best done by using other peoples body heat. Surround the patient front and back, like a human sandwich - the most effective way is to have skin to skin contact.
- If you are in a shelter, keep air movement to a minimum so that your own and other peoples' breathing warms the area inside. It may also be possible to heat the space with a small stove.
- Very few people carry a sleeping bag on a day trip, but if you have one with you, put the patient in the sleeping bag, ensuring all wet clothes are off. Skin to skin body heat should be applied where possible.
- Let the patient sit up, as a fall in blood pressure may occur.
- Rub or massage the limbs.
- Give the patient any alcohol.
- Warm the patient suddenly, as this may cause heart failure.
- Give fluids if the patient is unconscious - the patient may choke being unable to swallow.
- Breathing becomes shallow and slow.
- Shivering decreases and will cease.
- Loss of consciousness - breathing and heartbeat becoming increasingly difficult to detect.
An unconscious patient should be placed in the lateral recovery position. Be prepared to begin Expired Air Resuscitation and External Cardiac Compression. By this stage, it is vital that the patient gets hospital treatment as the situation is critical.