Cold water immersion

It’s important to recognize…

– Last Updated: Jan-19-13 10:26 AM EST –

...that a given person's response can vary dramatically, too. The fact that this guy seemed relatively unfazed does not mean that he would be under different circumstances. There are a lot of variable factors involved.

I'm speaking from personal experience here. I've spent a lot of time in seawater in the 40's and even as low as 30 degrees, without any problems. However, the one an only time I experienced the gasp reflex was in water in the 50's, on a warm day when I was completely relaxed and comfortable.

You can't predict it, so it's best to avoid it as much as possible by dressing properly.

How do you know that the risk is

– Last Updated: Jan-19-13 5:57 PM EST –

"very high"?

And, as a researcher, I *never* gloss over bad interpretations of research results.

See how many on here are willing to be guided by bad studies and limited interpretations.

Being “completely relaxed and
comfortable” is exactly the wrong preparation for withstanding immersion in cold water.



None of my cold water immersions have ever occurred when I was “relaxed and comfortable.”

You’ve often told us about …

– Last Updated: Jan-19-13 6:09 PM EST –

... diving into the pool in springtime to do some kind of job on the drains, but diving in and knowing you will do so is not the same is being dunked without warning or when under stress. Not only do I expect that being in control and prepared for what is about to happen makes one more able to control unwanted inhalation, how does one "gasp" and take in enough water to be deadly when already holding a full breath of air? A person can only inhale "so far".

The only case of gasp reflex I've actually read about was a guy who unexpectedly fell out of his canoe in the Boundary Waters while fishing in early summer, and though he was a decent swimmer, his partner said he simply sank. They figure he must have inhaled a lot of water almost instantly to not at least pop back to the surface a couple of seconds later like any normal person with swimming skills would do. Yes, that's not an example of will happen due to an unexpected dunking in cold water, but it is an example of what can happen, and it's enough to make me want to be careful.

Personally, I'm a fairly good swimmer but I've always had some trouble controlling my breathing during my first few seconds of swimming in very cool water. I've never actually swam in cold water, but I don't expect I'd do well in those first few seconds if not wearing proper clothing.

Any guess on his BMI?
The amount of insulation you carry on your body can have a big effect. I lost about 30 lbs and cold water affected me a lot more. Middle aged overweight women also are more likely to survive long immersion in cold water than young athletic men because of their body fat composition. Strange facts you can find about statistics of accidents. If he was in freezing water and was not shivering or expressing discomfort that’s pretty impressive.

Don’t UNDER estimate !!!

– Last Updated: Jan-19-13 9:46 PM EST –

Betting against mother nature is perilous.
She wins more often than the human do.

http://en.wikipedia.org/wiki/Hyperventilation

Cold water can cause humans to breathe faster/deeper
than they normally do when they are comfortable.

Getting a splash/wave at the wrong time (inhaling)
will cause the body to close the larynx and seal the trachea.
It's called a laryngospasm.
It's the start of drowning.





People
tend to underestimate the effects of cold water upon them until they experience it. This isn’t a surprise, considering that this is the case in most human endeavors.



Individual survival time is wholly dependent upon individual response to cold water. Those who immerse themselves in cold water routinely can withstand the conditions better than those who don’t. Just as people in Wisconsin seem to enjoy cold snowy weather that I would avoid, given a choice.



As seen later in the video, when the threat of sinking was removed (by PFD), the response of the same individuals was less severe. Stress and fear will decrease one’s ability to perform. This is true in all situations, but the video makes this point clear about cold water. Remove the immediate threat of drowning and the swimmers fared much better.



If you can stand colder water than these individuals, good for you and I expect your reactions and survival times to be well above average. Unfortunately, you don’t always have the luxury of calmly rescuing yourself when you are with others in cold water conditions.



Even though I can survive the conditions where I paddle and have routinely been in sub 55F water for hours at a time, when I paddle with others I dress as though I will have to jump in and tow one of these individuals to shore. My personal safety becomes dependent upon the skills, tolerances, and judgement of those around me when I choose to paddle (or do other water based activities) in a group.



When paddling with a boy scout troop down the Sacramento River (Red Bluff to Redding, water temp in the low 50’s according to the sheriff), I found myself performing several rescues over the course of the 3 day trip (most on the first day - no surprise there). The boys who went into the water were wearing PFD’s, but due to their small body size and lack of adult thermal protection (ie. fat), became chilled and frightened (and thus less able to survive) in just a couple of minutes. Getting these youngsters out of the water quickly became really important.



Consider your ability to survive cold water one of your survival advantages, but don’t assume that because it won’t happen to you that you are safe when you are on the water with others who lack that survival advantage.



Rick

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.