Backcountry Safety: Surviving Cold Water Immersion
This article was published in the Backcountry Safety Column of the "Hunt Alaska" Magazine, Summer 2015.
Story by Jon Hunt.
Accounts from the Titanic tragedy document there were not enough lifeboats for all of the passengers. Survivors in lifeboats heard screams for up to two hours coming from the victims floating in lifejackets who were eventually silenced by a chilling hypothermic death. You may wonder how this catastrophic event is relevant to Alaskan hunters. This testifies to the fact that personal floatation devices (PFD’s) save lives. This isolated account also demonstrates that hypothermia is not a quick event, but rather a process of the body temperature lowering over a duration of time. Contrary to popular belief, hypothermia rarely kills victims of cold-water immersion; usually they drown as a result of a Cold Water Shock Response.
I spent my formative years in Virginia Beach, Virginia, working as an American Red Cross Lifeguard Training Instructor, and Water Safety Instructor. This was also the location of my first open water scuba diving experience. I consider myself a confident swimmer. However, none of these experiences helped me to realize the real effect of cold-water immersion on the body. In hindsight, my first few years in Alaska, I vividly recall saying things like, “I don’t need a lifejacket, I am a good swimmer, I’ll be fine if I fall overboard…”
I was soon humbled on a frigid day in Whittier when I did my first Alaskan winter scuba diving trip. It was February and blowing snow, very cold. I made proactive efforts to wear a high quality dry suit, thick undergarments, a full hood, gloves, and boots. Even though only a small portion of my face was directly exposed to the frigid water, it was enough to allow me to mildly experience the “cold water shock.” As my face hit the water I instantly and involuntarily began to rapidly breathe through my regulator. This was amazing to me, unlike anything I had ever experienced. It’s hard for me imagine the gasping reflex that would happen in a sudden experience of my body unexpectedly hitting the cold water, for example, a capsized boat.
Dr. Gordon Giesbrecht, director of Thermophysiology at the University of Manitoba, coined the slogan, “One Minute – Ten Minutes – One Hour” to summarize the first three stages of surviving a cold-water immersion scenario.
The Cold Shock Response first happens when the body suddenly hits the cold water. The body’s initial reflex is to suddenly gasp or hyperventilate. The key concept to remember here is to “chill out” and stay alive, keep your head above water and get your breathing under control. This stage can last anywhere from a few seconds to a couple of minutes. Wearing a PFD is a real life-saver in this moment, even for the best of swimmers. If the victim’s head is under water when this happens, it can lead to immediate drowning due to inhalation of water. Holding one’s breath underwater is nearly impossible due to the physiologically challenges that occur. A cardiac emergencies may also be triggered by this event.
Upon surviving the cold shock experience and get your breathing under control, only a short window of time (about 2-10 minutes) is available where enough strength and dexterity exists to save oneself before becoming incapacitated.
Despite this fact, Dr. Giesbrecht teaches that a long time (1-hour) is available before death by hyperthermia. At that point, don’t thrash around -- it will only lead to increased heat loss and exhaustion. Water conducts (takes away) heat from the body about 20-25 times faster than exposure to air. This fact dictates our best chance of survival is to get as much of the body out of the water (onto the ice or capsized boat, for example) and stay as still as possible. Even though unconscious, rescue and survival is still possible. Victims have been found unconscious with their beard or clothing frozen to the ice, and have survived.
Dr. James Wikerson describes Cold Incapacitation as the phase in which the body desperately strives to maintain a homeostasis of a normal core temperature. The body attempts compensation by constricting blood vessels in effort to shunt blood away from he extremities to the body core. Dexterity rapidly diminishes during this stage, so advantage must be take of the precious 10-minute window to make survival decisions.
If self-rescue is not possible:
If you survive the Cold Sock Response and Cold Incapacitation stages, only now are you are a candidate for the onset of Hypothermia. The prolonged exposure to the cold will continue to diminish body core temperature. Risk of death in ice-cold water takes most people more than thirty minutes. Even after a person becomes unconscious in cold water, they may possibly stay alive another hour more.
The reality is that most cold-water submersion victims don’t die of hypothermia, they drown. This reiterates the significance of wearing a PFD, adequate clothing, and carrying, on your person, any survival tools on which you plan to rely on.
Remembering the slogan, “One Minute – Ten Minutes – One Hour” may give you a fighting chance!
Giesbrecht, Gordon. Wilderness Medical Newsletter: Principles and Practice of Extended Care and Rescue; Frozen Mythbusters. Vol 15, No. 6, (2004).
Wilkerson, James. Medicine for Mountaineering & Other Wilderness Activities, 6th ed. Seattle: Mountaineers Books, 2010.