Don't forget about all forms of risk from cold water. Hypothermia is estimated to cause around 15% of cold water fatalities. Where hypothermia tends to come more into play is when there is personal flotation which diminishes some other cold water problems but can involve extended immersion. And of course as paddlers we are typically going to be using a PFD around cold water if we have any sense at all.

• Cold Water Risk Not Just Hypothermia - Hypothermia Myths And The Truth About Cold Water
  1. 4 Staged Risks (what do they mean for paddlers) - Serious exposure typically begins with the initial plunge into cold water (but read the stories below about Cold Incapacitation from long term exposure to cold weather that can also kill (even without extended initial immersion)). Intial Cold shock is probably a greater risk for boaters who have been relatively inactive particularly if they are not wearing a PFD, in contrast to surfskiers who typically will be generating quite a bit of heat (and always have a PFD on when paddling in cold water we hope!) when they first hit the water. Cold Incapacitation may well be less anticipated or appreciated by under-experienced paddlers - in terms of how fast body motor skills can deteriorate. Even with significant immersion protection, your hands can rapidly lose coordination and facility (if you have enough glove to protect the hands in seriously cold weather they won't have a lot of dexterity anyway because of the glove interference). After Cold Incapacitation is already interfering with your ability to remount or paddle or use a radio putting you in serious trouble, Hypothermia will quickly follow and start to interfere with your decision making. The decisions you make before Cold Incapacitation is in full force may be the ones that save you - while you still have the body control and sense to execute them - like calling for help on your radio.
  2. Cold Shock
     • Subject for 2010 Article
       • Subsequent discussion of Hypothermia
  3. Cold Incapacitation - often described in reference to drownings where people without life jackets lose the capacity to swim, but can be equally as deadly in terms of losing coordination for remounts, paddling, making a fire (To Build a Fire)…
     • The following 2 stories emphasize the underestimated risk of cold incapacitation for very experienced paddlers (who have not adequately guarded against cold risk) even while they are staying completely or mostly upright but exposed to long term cold, another way cold can also be deadly - in part because it can sneak up on you if given the opportunity. The risk is of course greatly accelerated for paddlers during an extended swim in cold water.
       • Ivan Lawler's Brush with Cold Incapacitation in the Great Glen Challenge
       • 4hr Back Country River Race in Cold Conditions Losing Coordination (Paddle stroke catching crabs, etc.)
  4. Hypothermia (watch Richard Forbes video above) Hypothermia has its own stages typically defined by ranges of body temperature and evidenced by symptoms. Symptoms in individuals vary at body temperatures depending on age, fitness, body fat, etc. Stage 1 (mild hypothermia) may overlap with Cold Incapacitation, but stage 1 also begins to involve cognition impairment which contains significant risk for paddlers and only gets worse with subsequent stages.
  5. Post Rescue Collapse (also termed “Circum Rescue Collapse” because it has been observed shortly before, during and after rescue Once rescued, after you have been immersed in cold water, you are still in danger from collapse of arterial blood pressure leading to cardiac arrest.

Risk Denial Even Among the Very Experienced

• "Not Me" Syndrome Silent Sports Magazine article about North Face founder, Doug Tompkin's death in cold water. The web site will allow several full views then with subsequent clicks on this link the site will hide part of the article behind a subscription banner.
  • Survivor's account (National Geographic - access may also be limited now behind a paywall or may insist that you at least provide an email address (local copy of article)) of incident leading to Doug Tompkin's death due to hypothermia
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