Cold water immersion

That’s exactly the point I’m making.
When I’m paddling a decked boat on cold whitewater, I’m prepared in my subconscious for the probability of flipping and rolling, or swimming. That reduces the effect of cold water shock. The other factor is proper gear, namely a drysuit or wetsuit, sufficiently insulated. The cold water shock response (better term than gasp reflex) is apparently mediated by the skin of the torso, though cold water on the face can elicit gasping.



Though googling on the gasp and cold water shock topics is somewhat disappointing, I found a few things worth reading, including a long post by one of those crazy people who swims in Lake Michigan in the winter. (They do wear wetsuits.) He describes how they can learn to suppress the cold water shock response, and even learn to love cold water training. Mind over matter.

Googling on gasp and on cold water
shock was mostly disappointing, because most sources exaggerate without casting much light, without discussing individual variation in response, and without discussing how one can become resistant to cold water shock. But here are a few links. The USCG slide show is pretty good. The Dworkin article recommends covering your face and nose as you enter cold water, but that doesn’t work for kayakers. An article by a guy who swims in Lake Michigan in cold water (in a wetsuit) describes how to build up resistance to cold water shock. And posts on a UK/Ireland forum provide shared experiences of swimmers surprised that their cold water response is much less. Note that if a link isn’t fully highlighted, you may have to copy the whole link and paste it in the address line.



http://www.uscg.mil/pvs/docs/coldwater1.pdf



http://www.swimclub.co.uk/forum/showthread.php?t=15335



http://openwaterchicago.com/category/owc-blog/tips-techniques/



http://www.lifesaving.com/issues/prevention-and-management-torso-reflex

cold water is like surgery…

– Last Updated: Jan-20-13 10:21 AM EST –

its all serious when its happening to me. When the water is cold, I believe its easier to dress comfortably on a cold day than a warm one. I try to dress for the swim. meaninging the water temperature. That can lead to overheating and discomfort when paddling. When the air temperature is chilly you naturally bundle up more to stay comfortable. I always protect the head with some sort of hood. I don't like rolling up and seeing big black and purple spots or having an instantaneous ice cream headache.
Rewarming after a swim is naturally harder on a cold day. I carry dry fleece and a sleeping bag in a lined dry bag for rewarming. I also have a lighter to build a fire. Where I have fallen short in my preparation is on warm days with cold water. Having a drysuit is not enough, you have to have sufficient insulation also. Hard to do a warm day. The "new" breathable fabrics help because the suits breathe a bit. I don't know if cold water multiplies the danger by 5x or some other magic number. What I do think is that its important to take it seriously. Many times I've shown up to paddle and thought I'm glad I didn't dress that way when I see how one of my buddies has dressed. I'm about as cheap as they come when it comes to buyin' gear but I don't skimp on the lifejacket or the drysuit. Bottom line, I don't like being cold but I like paddling when it is cold outside. So I plan for the swim, try to be safe but sometimes have to sacrifice comfort while paddling. Beats wearin' the old orange horse collar lifejackets when I was growin' up but overheatin' ain't a whole lot of fun either. If you truly dress for the swim sometimes you're a tad uncomfortable.

Let me clarify

– Last Updated: Jan-20-13 11:24 AM EST –

I was relaxed and comfortable because I knew what I was doing. Not only was I expecting to be in the water, I was demonstrating sculling and rolling at the time. This was not a case of unexpected immersion, it was a case of an unexpected REACTION to an intentional immersion.

That's the point I've been trying to make; the gasp reflex is unpredictable and it can happen even if you're prepared for immersion, even if you've never experienced it before. You may think you're immune to it, but if I were you, I wouldn't bet my life on it. It seems that you take reasonable precautions, but dismissing studies and other evidence does not help to promote cold water safety, especially considering that some of the people who you influence may be more susceptible to the gasp reflex than you are.

You may want to nit-pick about the details or methodology of gasp reflex studies, but the facts are that it happens, it's unpredictable and people die because of it, so paddlers need to take precautions to avoid it. That's what needs to be emphasized if we're promoting cold water safety.

Let’s be honest here

– Last Updated: Jan-20-13 7:48 PM EST –

Most people simply won't intentionally run tests
upon themselves with various clothing wading
out into ice cold water over their head.

They will get severely surprised when the boat flips.
Almost all will hyperventilate after being fully submerged.
They will feel a moment of panic.

Practice helps - but most won't do on the water in winter.
They see a sunny, relatively warm air temp day,
and go paddle very, very cold water, on a whim,
and be ill-prepared for that capsize event.

Since we’re agreed they should be
properly attired, is there an issue remaining?



But here in the SE, the experience and behavior of most whitewater paddlers seems to have been better than you would expect.

One swallow doesn’t make a summer.
That may be on your IQ test. Your surprise experience does not supply us with generally useful evidence for the variability of cold water shock, or for whether one should be able to prepare for it.



Your relaxation would not be good preparation for onset of space sickness. Astronauts were told to tense up, to develop a sympathetic swing (rather than parasympathetic) in order to prevent space nausea.



I would bet the same is true for cold water shock. You have to provoke peripheral vasoconstriction and a preparatory increase in blood pressure and heart rate. Partly because that’s what is going to happen once that cold water hits your skin.



If the state of the voluntary and autonomic nervous systems are preset for cold water shock, there will be much less variance in outcome.



Incidentally, in my biofeedback research days, I knew a Canadian researcher who showed that people could develop reliable hand-warming through Pavlovian classical conditioning. He developed the approach so that mechanics could briefly take their hands out of heavy protective gloves to do work requiring fine dexterity. Another example of how a variable reflex can be skewed, reliably, in the desired direction.

That’s all well and good…

– Last Updated: Jan-21-13 11:03 AM EST –

...but it's completely irrelevant to the average person who's just interested in paddling their kayak. You simply cannot assume that anyone here is going to invest the time and effort to train themselves in the manner you describe. Heck, it's hard enough just to get people to dress properly!

Honestly, this is one of the most ridiculous discussions I've ever seen here. YOU apparently dress for immersions and take other precautions - such as mental and physiological preparation - yet you turn around and imply to OTHERS here that gasp reflex is nothing to worry about! How ridiculous is that? As someone who claims to be a scientist, surely you can see in inconsistency in that, can't you?

Honestly, what is your point? If it's just to expound upon your qualifications in physiology or scientific research methods, fine YOU WIN. With that out of the way, how about we discuss how to help others stay safe on cold water?

People who don't know any better need sound, safe advice. Those who are trying to avoid spending money or who simply don't want to do the right thing don't need others to enable that behavior by adding to their list of rationalizations.

The bottom line is simple:
- Gasp reflex happens.
- It is not 100% predictable or controllable.
- It kills people.
- People paddling on cold water should take precautions to avoid it.

Can we at least agree on that much, for safety's sake?

sounds prudent to me
Given the uncertainties remaining regarding gasp reflex (and there are uncertainties), I’d agree.



You also hit on something that bothers me about these discussions. Thanks.

It’s refreshing…

– Last Updated: Jan-21-13 6:05 PM EST –

...to see someone generalize so broadly in todays' Politically Correct society :)

But for what's it worth, this time around willi is right, no amount of rolling in the pool or in summer prepares you for a capsize in ice-cold water with a bit of clapotis around and icy wind above it. Drysuit, neoprene hood, does not matter - first time you go under your brain freezes, your muscle control goes all haywire and suddenly you discover your roll is not as bomb-proof as you thought.

It's like listening to the Rescue yapping about ice-skaters having to carry chest spikes to help them in case they fall in - like a Joe Average skating on a lake in "regular" winter clothes will be able to adequately employ them once they fall though and will be left swimming, bogged down in wet clothing and skates.

Practice, practice, practice. Nothing else.

Gasp
For those that believe that the gasp reflex can be avoided with practice; how do you explain all of the dead people immersed in cold water?



A county Sheriff died at Lake Tahoe recently during his shift in a patrol boat. He got off the power boat without a PFD, stepped in the tender and went over the side and drowned. It was about 9 feet of water and several people watched him go in and did nothing about it. Dress for immersion and wear a PFD.

Tahoe is a bit colder
this time of year and I am finding references (nothing completely reliable as to current surface temperature, just generalities) to about 50F or a touch cooler. This is certainly cold enough to cause hypothermia in a short period of time, but should be survivable for the time it would take to perform a rescue.



I cannot find a reference to the drowning you indicate online at the moment. I have found several others with similar elements (water depth, fell off dock), but none where the observers failed to at least attempt to lend a hand. There is one where an individual jumped off his boat and tried to swim to shore, but drowned, probably due to the cold.



The surface temps during winter are usually cited as between 40-50F (probably closer to the higher end of that scale, though near shore, the shallow edges of the lake may have ice). Really unpleasant conditions in which to try a rescue without immersion protection.



Rick

Perhaps…
…the Sheriff was weighed down by his standard-issue gear (gun, handcuffs, radio) and couldn’t shed them in time. Add the cold water, possible gasping and you’ve got a lethal mix.

Beyond the video

– Last Updated: Jan-22-13 11:38 AM EST –

Worth a look, and a second to re-think cold water :

http://umanitoba.ca/faculties/kinrec/media/cold_water_physiology_survival_treatment.pdf

It addresses many of the items people brought up.
Professor Popsicle created the info to save lives.
It's worked and people are changing their perceptions.

Cold water shock happens. Gasp
“reflex” I’m not so sure.



I believe in treating people, including paddlers, like adults. If they want to know about what happens when they drop into cold water, I tell them it isn’t absolutely nailed down, they might become helpless, but they might also be able to swim out of the situation. And I try to give them the facts on both sides.



This reminds me about how you made up “facts” about stretching gaskets while insisting that only trimming can truly work. Spreading the “truth”? I don’t think so.

Incidentally, what is the “party line”
you’re trying to spread on cold water immersion?



Not to do it? But people will recreate over cold water.



To wear a PFD? But that was already clear from the video.



To wear a wetsuit or drysuit? Most people know about wetsuits. Problem is, they may not anticipate falling off a fishing boat. And, because they perceive that risk as low, they may not want to wear an uncomfortable garment.



To give up if they fall in cold water without a PFD or drysuit? Because then there’s no hope?



What fatalism-for-the-unwashed-masses are you preaching?

So now you’re going…

– Last Updated: Jan-23-13 6:59 AM EST –

...to try to put words in my mouth? That's how you have a "scientific" debate? Yeah, that's really some kind of "scientific method" you've got going on...

What I'm trying to do is to educate people about the dangers they will encounter when paddling on cold water and what they can do to protect themselves. Winter paddling can be a blast, but the margin for safety is much thinner than it is in summer conditions, so being prepared is critical.

That's a lot more useful than your pointless arguments over semantics that do nothing but divert attention from the real issue. I doubt that anyone here gives a damn about whether gasping is a technically a "reflex" or not and it doesn't matter. What's important is that it can happen and it can be deadly, but one can minimize the risk through proper dress.

And for the record, regarding latex seals, I have never said that "only trimming can truly work". What I have said is:

- Stretching latex seals damages the material. As a "scientist", you should understand that, since it requires stretching the material beyond its yield point.

- Stretching seals takes way too long and most paddlers end up dealing with unnecessary discomfort during the process, which can be completely avoided by trimming them.

- Depending on the size of the seal and the size of one's neck, you may not be able to stretch a seal enough to fit properly.

-Trimming seals is fast, effective and doesn't damage the material. That's why the companies that manufacture SEALS recommend trimming them, regardless of what garment manufacturers that use their seals may say. That's also why them mold trim rings into them.

Satisfied?

Actual swimming/rolling in ice water?
This discussion is important and interesting but rather short on personal experience with cold water immersion and rescue.



Who here has actually swum or rolled many times in ice cold water? What happened?



I was a Sierra Nevada and then New England whitewater canoeist (open and decked) for decades. We began boating in lower New England in February and followed the snow melt line up to northern New Hampshire, Vermont and New York into late April and early May. Thus we were always boating on recent snow melt rivers that weren’t much above the freezing temperature of 32 degrees F.



There were swims by paddlers and rolls by the kayakers on almost every trip. In addition, we were often dragging our boats through knee deep snows on the banks after spills, around dams and around rapids.



I remember my first trip into the Hudson Gorge in April. The air temp was in the 20’s. Everyone’s boats had ice sheets on the hull and icicles dropping from the gunwales. The guys with beards had them frozen. The painter ropes on our decks were frozen in their coils. Three of us swam in Soup Strainer.



I honestly don’t remember anyone on any of these ice weather swims and rolls swallowing water due to a gasp reflex (in fact, never heard of it) or being incapacitated by cold shock from swimming to shore or rescuing their boats. Sure, people sometimes got cold during and after swims, but everyone I recall got back in their boats and kept on paddling after a swim (or roll).



Of course, 100% of the paddlers were always wearing life jackets, and everyone was always wearing some sort of protective clothing. In the 70’s you would see some wool-only clothing but wetsuits were pretty much de rigeur on whitewater. Drysuits came on slowly in the early 80’s and probably had been adopted by a majority of the paddlers by 1990, though not all.



Very few paddlers wore neoprene hoods or face masks. Most wore gloves. All kayakers and most canoeists wore helmets, with perhaps a thin wool or pile cap underneath.



Other factors that perhaps contributed to the lack of cold water medical emergencies on rivers:



– Whitewater swims are usually relatively short. Five minutes of immersion would be a long swim.



– The paddlers who wore wool-only or wetsuits would typically bring an extra set of clothes to change into after a swim.



The primary thing I took away from Professor Popsicle’s videos was the importance of wearing a life jacket.



The danger of extended immersions are obviously much greater in ice cold water out in the middle of a large lake or the ocean. None of us did that.

There are several factors
Wearing immersion clothing that covers the chest makes a big difference. The fact that the paddlers probably had cold water splashing on their faces and necks would tend to desensitize them to sudden immersion, since their skin is already wet and cold. The fact that swims are commonplace prepared them psychologically.



Gasping tends to be instantaneous when you become immersed and it eases over time, so the length of a swim is not an issue, though it obviously does affect whether you lose motor control and/or become hypothermic.

Ocean vs. River
Those of us who paddle the oceans rather than inland rivers have a lower chance of encountering water that is sub 50F, unless we live north or south of a certain line on the map. Those who do paddle in those icy conditions have a notoriously bad survival rate in accidents. Going as far north as Vancouver means paddling on sub 50F water and the survival rates there, compared to say the 52-55F water I commonly paddle, are low enough to be horrifying.



Oceans don’t allow for “short” swims to safety. Paddling safely on the ocean often involves moving sufficiently off the coast to avoid the worst conditions (boomers, clapotis, and breaking surf). If you add ice to the mix, especially moving ice which can be between you and a shore that is notoriously devoid of shelter and resources (as you go further north), and the need for thermal protection well exceeds what one may choose for “short” swims on a river.



And even on rivers, terrain is a factor. Odds are that one will capsize in rather fast moving water, often found between high walls of a cut canyon (since fast moving water and rock often creates those kinds of conditions and these conditions prevail on many rivers here in the west). There may be beaches accessible, oxbows, warmer tributaries, etc. along the river, there just many not be one at the point of capsize.



So, my general rule is to be ready to swim for an extended period of time in the water. Strainers, foot entrapment, etc. can mean a very long time in the water before a rescue can be executed, even if the conditions do not offer an immediate threat of death.



I am not going to offer a statement that the “gasp” reflex happens or not, but I’ve seen people unexpectedly fall into cold water and it surely looks like the first thing they do is pop their heads above water, swim ineffectively, and try to gasp for air with their noses to the sky while panting like Lassie. Whether or not this happens underwater or not isn’t really important. Anyone in this situation, moving water or not, is in a life threatening situation and they know it. Panic may well set in, decisions become instinctive (and often wrong), and the chance of survival decreases.



I just finished reading about the divers who discovered a U-Boat off the coast of New Jersey and the sad stories of those (quite accomplished divers) who died investigating or trying to take trophies from the wreck. It is a classic example of the same type of situation where, if everyone stays calm, many of the accidents will not occur, but in cases of extreme fear, everything falls apart and people die.



In one example, a father/son buddy team both died because a temporary entrapment left one of them without air and the other seriously depleted. There were rescue bottles of air available, but in the silt and fear, they ignored their compasses and swam 180 degrees in the wrong direction along the length of the hull.



Frightened people tend to make horrendous decisions and often take others with them down the path of risk. We lost a father/son duo on the coast this year because they threw a stick for their dog into a tidal rip. Neither was dressed for such conditions (52F water).



When the dog had difficultly coming back in against the rip, the son went to help the dog. The path of failure compounded when the dad jumps in to help the son. Bad decision one spawned bad decision two, both died. The dog swam out of the rip and made it to shore. Their fear, inexperience, lack of basic water safety, etc. made this an accident just waiting to happen, and I see this level of ability and judgement EVERY time I go to a beach in California.



In my opinion, we need to tailor these discussions along lines of “what if I encounter…” not along lines of, “I can survive immersion in absolute zero vaccum conditions and anyone who can’t is an idiot,” since those of us who can survive expected conditions probably won’t have the kinds of problems that are described here.



And nature has a HUGE intolerance for arrogance. You and I may well have all the skills, judgement, knowledge, and tools/equipment needed to survive expected conditions only to find that nature decided to change the conditions on us without asking our permission.



I didn’t mean to make this a diatribe, but I do want to remind everyone that life is what happens when you make other plans.



Rick