COLD WATER PADDLING & HYPOTHERMIA
Cold water paddling introduces magnificent, wild, and challenging worlds to our adventuring. Clouds of new bird species, hundreds of whales, vast and remote wild spaces are open to us with our ability to paddle safely and wisely in cold environments. Sea kayaking began in the cold reaches near the Arctic Circle over 4,000 years ago.
What is the water temperature? Is it raining, windy or cold? How long will I be wet? How long will I be in the wind? Do I have any safety spots? How cold is it for my body? How active am I going to be? What have I recently eaten? How hydrated am I? What is my skill set?
The most important skill sets for cold water paddling are effective common sense and reliable judgment. How switched on are you to be out when the margins are small the backup remote?
The Hypothermia Danger
To enjoy cold water paddling we need to avoid hypothermia. Hypothermia occurs simply when the challenge of wet, wind, and cold overwhelms the body’s ability to produce and to retain heat. Hypothermia can arise from a several minute unpredicted rescue in cold water; from days of rainy, cool conditions; or from weeks in a weakened, sickly state.
Hypothermia Treatment Theory
The remedy is simple. If prior planning and good judgment fails to avoid the windy, wet, cold challenge, then we need do 3 things:
- Minimize or reverse the cold challenge.
- Increase your heat production with exercise, food, and water.
- Increase heat retention with dry insulation and avoidance of conditions.
Sudden immersion in cold water can create a gasping reflex infusing the inner body with very cold water and accelerating into a severe physiological challenge. Sudden immersion can also trigger immediate fibrillation and cardiac arrest.
Equipping for Paddling
The first rule for paddling in cold climates is: dress for the water temperature. Our route selection and clothing needs to protect us from at least two of the three primary exposures: cold temperature, windy conditions, wet insulation. (Let’s not forget the dangers of overheating and exposure to the sun.)
- Insulation materials: Synthetic clothing dries quickly and is relatively warm when wet. Cotton + wet + cold kills; it dries very slowly and evaporative cooling quickens heat loss when wet.
- Layering: Wicking fabrics to keep dry layer next to the skin; polypropylene/polar fleece for insulation; windproof layer to trap warmth; waterproof layer to protect insulation.
- Wetsuits (neoprene rubber suits) trap and insulate a layer of water next to the skin. Good for in the water and swimming, but cold when wet in the wind. Can be uncomfortable if dry for long periods. Different thicknesses of neoprene for different levels of warmth, one level of warmth per suit = different suits for different seasons.
- Drysuits afford us a moisture barrier layer to keep our insulation dry and keep wind out. Add or reduce insulation under the dry suit for temperature control. Good for floating but not for swimming; comfortable in the boat for long paddles. Can be too hot, which increases danger of fluid loss and hyperthermia.
- Extremities must be protected. Protect the head area - protect your thinking, including the throat area with wool/neoprene head gear. Loss of use of hands or feet could prevent us from effecting a rescue, preserving valuable gear, or removing ourselves from the cold. Consider pogies or functional gloves for hands, wet or dry boots for our feet. Consider wool or synthetic materials, and don’t forget your eye protection. If you have a $10 head, wear a $10 helmet.
- Emergency/spare clothes are critical equipment components to help change the cold challenge. Need to protect from temperature, moisture, and wind (and sun.) How and where do you pack them? How much do you carry?
- What do you carry to lessen being wet, avoid the cold, and lessen the wind? To reduce the cold challenge, increase both heat production and heat retention?
The Science of Hypothermia
Our bodies effectively compensate for Earth’s climate and regulate our exercise, food, water, and health states to maintain a 98.6 degree core temperature. It’s an amazing balance. Mild hypothermia results from a core body temperature of 94-98 degrees; severe hypothermia occurs when the body temperature falls below 94 degrees. Even mild hypothermia requires immediate, speedy, and effective treatment. When challenged, our shell/core effect increasingly reduces blood flow to the skin to reduce heat loss; institutes vasoconstriction which increases hypoxia of extremities; induces shivering to produce heat; and implements cold dieresis which dehydrates us.
100% of those hypothermic are dehydrated. Consider a rectal thermometer for evaluation as needed (gives better core temperature reading).
As mild hypothermia sets in, we may lose motor skills, have increased muscle rigidity, slurred speech, pale and cool skin, shivering, loss of judgment, and our mental state may become lethargic, withdrawn, confused, irritable, or hostile. Our alertness will lessen.
Prevention & Treatment
Use common sense.
- Constantly evaluate the risks of the cold challenge.
- Maintain hydration and fuel.
- Pay attention to each other and catch it early. Listen for the "umbles": mumble, fumble, stumble, grumble.
- Help and Huddle.
- Remove from the cold, the wet, and the wind as possible.
- Change to dry clothes.
- Apply hypothermia wrap and vapor barrier.
- Evaluate the MOI (Mechanism Of Injury), the nature of the cold challenge, length of time, depth in body.