This column was first published April 1, 2006
We’re all about paddling this week. The on-water season already is under way for some, and for others it’s right around the corner.
Before you drag out your boat or canoe and head for the nearest ice-free water, though, take a few minutes and study up on what cold water can do to you — like kill you — quickly. And plan to attend the free sixth annual Paddle Smart from the Start safety symposium at the Bangor Y on April 28 (more on that below).
At a Maine Association of Sea Kayak Guides and Instructors meeting on March 23, we got a great review of hypothermia and cold water immersion from Dr. Dave Johnson of Wilderness Medical Associates in Portland, some reference material from Gordon G. Giesbrecht (known as Dr. Popsicle), and a couple of educational pamphlets by Chuck Sutherland, who authored an article “Cold Water Paddling” published in Atlantic Coastal Kayaker in December 2001.
Giesbrecht is the man to go to when it comes to study of hypothermia. He should know. He’s purposefully fallen through thin ice (rescue personnel were standing by) with the cameras running to document what happens to someone suddenly immersed in frigid water. (Check out youkonman.com for Giesbrecht’s various cold water studies.)
In the video we watched, he was dressed in cross country ski gear (skis and all) when he “broke through the ice.” His sometimes labored running commentary talked us through the three phases of the body’s response when immersed in cold water: cold shock, cold incapacitation, and long-term hypothermia.
The cold shock phase (the first 3-4 minutes), he says, initiates “peripheral vasoconstriction, the gasp reflex, hyperventilation, and tachycardia … [that] can respectively lead to hypocapnia (less than the normal level of carbon dioxide in the blood), the inability to breath-hold, hypertension, and increased cardiac output, all of which can cause sudden death either immediately or within a matter of minutes after immersion in susceptible individuals.”
That sounds like fun, no?
Next comes cold incapacitation (for those surviving the cold shock response). This involves “significant cooling of peripheral tissues, especially in the extremities [and] continues to occur for the first 30 minutes of immersion. This cooling has a direct deleterious effect on neuromuscular activity. This effect is especially significant in the hands where blood circulation is negligible, leading to finger stiffness, poor coordination of gross and fine motor activity, and loss of power … making it difficult, if not impossible, to execute survival procedures such as grasping a rescue line or hoist. … Thus the ultimate cause of death is drowning either through a failure to initiate or maintain survival performance – i.e., keeping afloat, swimming, grasping onto a life raft, etc., or excessive inhalation of water under turbulent conditions.”
More fun, no? You’re dead – again.
Let’s say you cheat the devil once more. What’s next?
That would be long-term hypothermia. Giesbrecht’s studies confirm the following: “The individual who survives the immediate and short-term phases of cold water immersion faces the possible onset of hypothermia as continuous heat loss from the body eventually decreases core temperature.” By the way, if nothing is done to stop this heat loss (that would be someone else coming to your aid), you’re dead because below about 86 degrees, your body can’t rewarm itself and you will die.
In an article “Accidental Hypothermia,” Giesbrecht says, “The factors that affect the rate of body cooling include the medium of exposure (i.e., water or air), ambient temperature, redistribution of blood flow between the body core and periphery; insulation on superficial layers (i.e., fat and clothing); and endogenous heat production (exercise and shivering).”
Shivering, he says, is an important factor in the body’s production of heat in an effort to prevent core cooling.
Even after you are removed from the water that has caused your body temperature to drop, there is a post-cooling effect called “afterdrop.”
In the video Giesbrecht remained in the icy water for 15 minutes. At that point all he could hope for was the arms of his jacket to freeze to the ice and hold his head above the water long enough for help to arrive and pull him out. He was incapacitated – alive, but unable to help himself. If his arms didn’t freeze to the ice, he would slip beneath the water and drown. At this point rescue crews rushed in and pulled him from the water on a rescue sled and got him into a warm ambulance to begin the task of rewarming him. And the effect of “afterdrop” was evident in his blue-looking face and dazed expression and slurred speech.
Rewarming involves stopping the fall in core temperature “and maximizing a safe rewarming rate while maintaining the stability of the cardiovascular system and correcting metabolic imbalances.” It can be as simple as shivering and exercise (mild hypothermia) or more complex (core temperature below 86 degrees and shivering has stopped) external/internal warming methods such as forced warm air, heating pads, hot water bottles, radiant heat, warm water immersion, hot food and drink, inhalation of heated saturated air/oxygen, warm IV fluids, and cardiopulmonary bypass. Needless to say, the advanced hypothermia victims should be treated by professional medical help.
In severe hypothermia the victim should be evacuated as rapidly and gently as possible and taken to a hospital.
How does this apply to paddlers?
Sutherland tells a story of two brothers, ages 10 and 18, whose canoe accidently capsized in 50-degree lake water on Memorial Day 1996 in the Adirondacks. High winds were pushing the overturned boat along. The younger brother, who was wearing a lifejacket, was promptly rescued. Minutes later, Sutherland relates, the older brother, wearing jeans, a light shirt, but no PFD, could not be found. He was not able to hold onto the capsized canoe for even the few minutes it took to save his younger brother. Divers found his body the next day.
Water removes heat from your body 25 times faster than air. Immersion in turbulent water or trying to swim can increase the loss dramatically. Survival time can be reduced to minutes. Strong swimmers, Sutherland says, without thermal protection, have died before swimming 100 yards in cold water. In water under 40 degrees (the ocean’s now at 37-40 degrees) victims have died before swimming 100 feet.
Dressing for cold water immersion, then, is key to survival. You need to dress in layers starting with (usually) a polyester layer that is highly vapor permeable, and top it with a middle layer(s) of insulation such a fleece, pile wool, or thicker polyester, Giesbrecht says. The outermost layer provides wind and moisture protection.
This outer layer for many is a wet suit. Others prefer a dry suit with latex gaskets at wrists, ankles, and neck that keep the water away from your skin. A neoprene hood will keep your head warm and neoprene booties and gloves will do the same for your feet and hands.
And on top of it all, put on your lifejacket, zip it, and cinch it snug.
If you capsize, try to get back in or on your boat immediately. Do not leave the boat. Learn self-rescue techniques and paddle with a partner. The two of you should know partner rescues as well.
Come to Paddle Smart
Now that you’re aware of the dangers of paddling on our cold waters, why not try to educate yourself a little more and come to our sixth annual Paddle Smart from the Start Safety Symposium. It’s coming right up. Be sure to mark your calendar for 5-9:30 p.m., April 28, and be at the free event being staged at the YMCA on Hammond Street in Bangor.
The event promises to have something for everyone who takes to the water by canoe or kayak, and I’ll guarantee everyone will come away with something they didn’t know before.
Take this kayaker’s survey and see how you score: Do you really know what to do if you or your friend capsizes? How do you plan a safe trip? How do you avoid the wind? How do you get help if you need it? What gear do you really need? What clothing will keep you most comfortable and may even save your life?
Interactive workshops include:
. Basics of Kayaking 10;
. Understanding charts and maps;
. Transitioning to Sea Kayaking;
. Planning a Trip to a Maine Island by the Maine Island Trail Association;
. Essential Equipment for Kayaking and how to pack it;
. Communication on the water and who to call for help, presented by the U.S. Coast Guard;
. GPS Navigation;
. Paddling in Moving Water;
. Choosing a Lifejacket you’ll want to wear;
. Demonstration of Kayak and Canoe Rescue Techniques in the Pool.
Displays in the gymnasium include: interactive children’s activities, choosing a paddle, fitting a lifejacket, maps and navigation, Maine Island Trail Association, Maine Outdoor Adventure Club, U.S. Coast Guard, Marine Patrol, Friends of Maine Sea Bird Islands, Maine Association of Sea Kayak Guides and Instructors, understanding and preventing Lyme disease, Penobscot Paddle and Chowder Club, Penobscot Riverkeepers, Maine Department of Inland Fisheries and Wildlife, Castine Kayak Adventures, and more.
The following businesses and organizations are sponsors: Castine Kayak Adventures, Epic Sports, U.S. Coast Guard, Maine Association of Sea Kayak Guides and Instructors, the Bangor Ys, the Department of Inland Fisheries and Wildlife, the Department of Marine Resources, Marine Patrol, and the National Safe Boating Council.
Check out this link for more information and pictures from past events: http://www.castinekayak.com/paddlesmart.htm.
Jeff Strout’s column is published Saturdays.