Here’s What You Need to Know: Cold Water Kills
Welcome to the three part Cold Water Immersion Series! The dangers of cold water cannot be overemphasized, especially in the spring, regardless of your location. Open ocean, inland waterways, inland lakes surrounded by shore on all sides. The threat of cold water is like cancer – it doesn’t discriminate, no matter where you are.
In episode one, I explore the four stages of cold water immersion, and share an important video demonstrating the effects of cold water exposure. In episode two, I discuss surviving being dunked in the cold and the process your body goes through the longer it stays in the water. This is known as the 1-10-1 Principle. In episode three I cover treatment – from mild immersion to hypothermia – as well as what you need to know and materials you need on board to safely treat someone pulled from the cold water.
Cold water is near and maybe not so dear to our hearts here on the Great Lakes. In the world of cold water immersion, experts speak of the dangers of water that is 59 degrees or less. The only time the water on Lake Michigan is warmer than that is the first two weeks of August! All joshing aside, the danger of sailing on cold water is very real. The coldest I’ve ever been in my life was in the middle of the night on a delivery across Lake Superior in July.
The Great Lakes are always cold, no matter the time of year.
Chart courtesy Great Lakes CoastWatch, NOAA
Hypothermia Myth Busted
This week, I’d like to share with you crucial information that comes from cold water guru Gordon Giesbrecht, aka Dr. Popsicle, a thermophysiologist at the University of Manitoba. Canadians know cold!
If you fell into cold water, let’s say 40F, in your street clothes, how long until you get hypothermic? Dr. Giesbrecht asked that question of over 661 cold weather enthusiasts. What he found is that 70% of people answered 10 minutes or less. Not even close! You can’t even get mildly hypothermic in under 10 minutes. As a matter of fact, your body temperature will go up first. The average adult can survive about an hour in cold water before losing consciousness from hypothermia and then go on to live about another hour after that until the heart stops. Only 4% got the question right. The reason this misunderstanding is important is that it affects the way we react. If you fall overboard and think you’re going to be dead in 10 minutes, the natural reaction is to panic.
Four Dangers of Cold Water
Cold water does kill, but hypothermia is only one way and it’s not even the most common way. There are actually four dangers of cold water:
The first stage lasts about one minute and is called the Cold Shock Response. It’s that first gut wrenching moment of hitting cold water. The lungs and the blood vessels react violently. The respiratory system replies angrily by gasping and hyperventilating. Our bodies are programmed to protect our most vital organs first, so the blood vessels in our arms and legs clamp down to keep the warm blood near our heart, lungs and brain. This massive constriction of the vessels puts stress on the heart and makes it work harder. This is especially dangerous to people with underlying heart problems. People panic, take on water and drown in this stage. 20% of people who die in cold water, die in the Cold Shock Response phase.
Stage Two is called Cold Incapacitation. It lasts about 5-15 minutes. Our nerves and muscle fibers get cold. Think of how much harder it is to trim sails, scroll through nav instruments or clip the spinnaker bag to the rail with numb hands. Cold nerves and cold muscles don’t work well. In the water, that paralysis is sped up. We will only get weaker and less coordinated, until our arms and legs won’t be able to keep our heads above water or we won’t be able to hold on to the capsized boat. Without a floatation device, even the best swimmer will drown in less than 30 minutes without ever dropping their core body temperature. In other words, it’s impossible to die of hypothermia without a life jacket on. You will drown first. 50% of people who die in cold water, die following cold incapacitation.
Hypothermia is Stage Three, which occurs 30 minutes or more after immersion. The only way to get this far is with a flotation device. It takes a long time to get here because the body protects itself by constricting blood vessels and by shivering. As Dr G says, vasoconstriction is like closing the windows and shivering is like turning on the furnace. After about an hour, we lose the ability to move and to shiver. We lose consciousness. We’re not dead yet. If we’re wearing a PFD that keeps our airway above water, we can last another hour or more, until our body temperature drops an additional 3-5 degrees and the heart stops. Hypothermia does kill, but only in about 15% of cold water deaths.
The final killer is Stage Four, Circum-Rescue Collapse. It can occur immediately before, during or after rescue and runs the gamut from fainting to death. They say if you’re pulled from cold water, you are two things: lucky to be alive and incredibly fragile. The stress hormones like adrenaline that served us so well to stay alive in the water by increasing our muscle strength and maintaining our blood pressure, can suddenly leave us with the mental relief of rescue. This alone can cause an abrupt drop in blood pressure and subsequent fainting or worse. The cooled heart is exquisitely fragile and the stress and exertion of the rescue itself can cause it to stop beating. Moving around during this phase can cause the cold blood from the extremities to rush back to the delicate heart, causing it to arrest. Standing upright can cause the blood to pool in the legs and the blood pressure to drop even more. There are countless stories of people alive in cold water, being attached to harnesses under the arms, pulled vertically up to an awaiting rescue helicopter, and arriving dead. Outside Magazine recounts a story that in 1980, 16 shipwrecked Danish fishermen were plucked from the icy North Sea after an hour and a half in the water. They walked across the deck of the rescue ship, stepped below for a hot drink, and dropped dead, all 16 of them. In fact, 15% of cold water immersion victims die in the process of being rescued. Out of the water is not out of the woods.
If all of this wasn’t gloomy enough, here are some sobering statistics from the 2007 study of recreational boating accidents by the United States Coast Guard (USCG Drowning Report) and the 2007 Lifesaving Society “Will It Float?” Report:
- In water between 70 and 79 degrees only 8% of accidents were fatal. BUT in water under 59 degrees more than 40% resulted in death. That means your risk of dying in water under 59 degrees is increased by 500%.
- 60% of boaters died in water under 50 degrees, 34% of them in water between 50 and 68 degrees.
- 43% of fatalities were within 6 feet of safety.
- The kicker, 90% were not wearing life jackets!
Watch Cold Water Dangers In Action
To illustrate his research, Dr Giesbrecht put eight U.S. Coast Guard volunteers through a series of exercises designed to teach us that the only way to survive a cold water immersion is to wear a life jacket. He also illustrates that we all have misconceptions about the time it takes to get hypothermic. Please watch the video carefully. It’s only 10 minutes and could save your life.
Thank you for listening. Stay tuned. Next time we’ll swing the pendulum the other way and discuss how to survive a cold water immersion. It’ll be fun! I’ve got your back.