Cold water immersion

I was shown this video during training and thought it might be useful to other paddlers. I’ve seen some other things along this line by the Coast Guard but they were for rescue professionals only. This is open source and very insightful. You might have to cut and paste the link.

Professor popsicle

– Last Updated: Jan-18-13 3:01 PM EST –

A famous guy regarding cold water paddling
Dr. Gordon Giesbrecht

Scroll ALL the way down his page.
He really has pushed cold knowledge forward

That video has been shown and discussed
extensively on pnet. I’m not impressed with it.

The video gives the impression that you will be automatically helpless trying to swim in cold water. But there are many counterexamples. I’m one of them.

A paddler should wear a PFD when paddling on cold water. A paddler should wear a drysuit over insulating layers when being cast into cold water is a possibility.

But what you can do in cold water is dependent on your expectations and motivations. The people in the Boot Camp video clearly had inferred that they couldn’t function at all in cold water, and sure enough! They couldn’t.

It’s bad science, like the gasp “reflex” and the drowning “reflex.”

Some may disagree with “bad science”

– Last Updated: Jan-18-13 8:35 PM EST –

There have been multiple scientists doing research
on the effects of ""cold water"" upon mammals

Professor popsicle built a career around it;
others on PubMed and elsewhere researched/studied it.

Scroll to the bottom of the link above
to see all the bad scientists
referenced and credited with assistance.

Bad science - hardly.
With 8 Billion humans on earth, do results vary, of course.

Lynne Cox swam a bit over 1 mile with penguins
in the Antartic 40 degree F sea water
for about 30 minutes.

Lewis Pugh did something similar, so it can be done

yeah . it’s a good vid. …

– Last Updated: Jan-18-13 9:20 PM EST –

...... it's been posted before here on , usually comes up during these winter months by somebody .

I think it's a good idea for someone to post it every winter because there are likely many new comers who haven't seen it . And probably still many who aren't aware of how dangerous cold water immersion can be .

I get g2d's point and realize not everyone will be as suceptable in such a short period of time , but out of the group of volunteers in the vid. , they all seemed to be very suceptable to the effects of cold water immersion (and that's only 45F.-47F.) , so it's my belief that most people will undergo the same things as the volunteers did in just as short a period of time .

I would consider it science because the experiment was initiated (volunteers in the cold water) , and the results are what happened (experiment's conclusions) .

Without proper cold water immersion clothing , I think it's realistic when they say you've got 6-10 minutes before you become severely disabled and unable to use your body for any self help (you a limp paralyzed monkey at that point) . With the PFD on , you have some time left for others to rescue you .

That’s my point. The cold water
scientists tend to talk as if everyone is doomed in cold water, but I’ve worked in cold water for short periods, wearing only swim trunks. No “gasp reflex”. No cold water paralysis.

The human reaction to cold water immersion is not reflexive, though it is strongly controlled both by what one has been told about cold water immersion (expectation) and by how one uses one’s mind to prepare for the ordeal.

So far as I know, no cold water scientist has studied the effects of expectation and of mental preparation on behavior in cold water.

Great comment
Great comment pilotwingz. That is was I meant when I posted this. I don’t think it is definitive on what happens to everyone but gives you some food for thought. The one thing it does show is how important a PFD is.

Last Saturday
that’d be January 12 2013

We took advantage of the 40 degree air temps and paddled the mighty Shawsheen.

at the takeout(fortunately), one guy missed a step exiting his boat and took a swim. Other than neoprene booties he was wearing street clothes.

Based on the ice on and in the water I’ll say that the water temperature was close to 32F/0C.

He was wearing his pfd and he was in the water for a little more than two minutes. The water was deep and the landing was small and icy so it took that long to get boats out of the way.

The rest of us were pretty worried.

He was not and showed little sign of discomfort.

He gathered his things and strolled over to his car where he dried off and changed into dry clothing that another guy had brought along.

He was coherent and showed no sign of shivering or lack of coordination.

As best as I could tell he is in his early 60’s and not an athelete.

Me? I was wearing a drysuit. I don’t care to be that cold.

Just an anecdote supporting the idea that we all respond differently to cold water.

IMO if you are going to paddle in cold water, you ought to fall in from time to time just to see how YOU respond.

The point is…
…that the “gasp reflex” is uncontrollable and unpredictable. It can happen to you, despite the fact that you’ve had cold water experiences when it didn’t occur. It happened to me in relatively benign conditions, despite the fact that I have spent a lot of time in much colder water.

While there is no “guarantee” that it’s going to happen and cause “certain death”, the risk is very high and it’s best to be prepared for it and take precautions to avoid it. Being dismissive of the research is not helpful in keeping paddlers safe. People already find plenty of ways to rationalize risky or irresponsible behavior; you may want to consider not contributing to that.

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.

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.

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.


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.

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.