It happens every year--people always misjudge cold water

The whole point of dressing for immersion is to reduce the chance of suffering from the gasp reflex, a spike in blood pressure and heart rate, and loss of breathing control.

These issues are less common in white water where periodic immersion is expected and people are much more likely to be properly dressed.

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I think one of the other characteristics of the gasp reflex is that there is a big difference in how susceptible different people are to it.

I used to live in the Southeast and regularly paddled on dam release rivers that had average water temperatures in the 50-60 degree F range because the water was released from the bottom of impoundments. I also paddle spring fed streams in the Ozarks with average water temperatures in the 55-60 degree range. In warmer weather I virtually never wore anything more than a splash top and often paddled in shorts and a T shirt, and sometimes nothing above the waist but a PFD.

I have been immersed in water of that temperature range either intentionally or not literally hundreds of times and have never experienced anything like a gasp reflex.

You should remember it is the difference in temperature that makes for gag reflex. For example it is summer in Fla. Air temp 99 +/- ā€¦Iā€™ve put the wet suit on to get in the springs and had that cold water gasp in 72 degree water.

Has anyone here heard of this phenomenon? Is it true in your experience?
Iā€™ve heard anecdotal evidence from two disparate sources and at two widely separated times that the gag reflex, in those who experience it, is triggered in part by how a person hits the water. One person was a regular ā€œpolar bear plungeā€ participant and the other a Finnish PHD from the Upper Peninsula of Michigan who regularly does the sauna/ice water plunge routine. Both obviously have some experience in cold water exposure and both claimed that if a person goes in head first they are more likely to gasp than if the brain has just that millisecond of preparation for the shock by going in feet first.

Does this jibe with anything anyone here has heard?

I havenā€™t heard that but it sounds as if it might be plausible. The experimental evidence certainly indicates that cold water immersion of the face is most likely to elicit a reflexive gasp and hyperventilatory urge, although it is not clear to me that it is essential. Of course, of the face is not immersed a gasp may be of no consequence.

But anecdotal accounts do tend to suggest that individuals who are most likely to be unable to control a gasp tendency are those who are taken by surprise, as it were, and are not psychologically prepared for immersion of the face in cold water. So maybe progressive immersion of the body from the toes up allows for some physiologic adaptation of the body to resist the urge to gasp.

It seems that it would be almost inevitable, given our specieā€™s cold weather hunting/gathering background, that evolution would, over time, select for a variation like thatā€¦ But youā€™d think if that were so it would make kayak rolling in cold water perhaps even more gasp inducing than, say, falling through a hole in the ice. And I donā€™t believe thatā€™s the caseā€¦

This issue has been discussed in multiple threads on this message board and its predecessor a number of times over the years. Here is one such thread: Is the Gasp Reflex Controllable or Not? - #8 by Celia

I certainly believe that the gasp reflex exists and is a mechanism for drowning in some cases. There are numerous reports of individuals who have gone head down into cold water never to resurface who had no evidence of having sustained any type of entrapment or head injury. A cold water gasp reflex resulting in aspiration with or without layngospasm seems to be the most likely mechanism of drowning death in these cases. But cold water immersion is also know to precipitate cardiac dysrhythmias in some individuals and that could also be a mechanism of sudden death or at least a contributing factor in some of these cases.

On the other hand it is clear to me that a gasp reflex that causes actually gasping underwater is not inevitable. My experience and that of many others who have been completely immersed in water of 60 degrees F and less many times is evidence of that. And it is not just experienced boaters. I have seen may whitewater rafting clients who have gone under in water temperatures in the 55-60 degree F range, often wearing nothing more than bathing suits and have done just fine.

Probably had no balaclava on or hood. Open or closed cockpit it will still happen. It can happen at 65Ā°F to some. Probably colder it gets higher probability of it happening.

Some, not all are susceptible to GASP. Need autopsy to see what happened.

Here in SW Michigan they sometimes have warnings on the local news on hot summer days that boaters should not just jump off their boats into Lake Michigan. If pool temps at the YMCA get down to 80 or below youā€™ll hear gasps from some people when they enter the water.

Ditto for the tip of the mitt, except the warnings are pretty regular. Especially in May when the tourists start heading up.

Training, familiarity, expectation, and personal physiology, as well as dressing for immersion can all affect susceptibility to the gasp reflex. Dressing for immersion seems to be the most effective prevention for the average person in most cases.

Thatā€™s what I rely on.

I just caught that an ancient response of mine was referred toā€¦

Whatever I said then, this discussion tends to get into apples and oranges. Someone who has been practicing rolling thus gotten by the initial panic moment can likely control their reaction to immersion into some chilly temperatures. Someone who has practiced wet exits to the point of being certain they can get out would be similarly protected.

Someone who has been unwilling to do such practice is less likely to have that control. Newer paddlers often include people who are at least reluctant, in some cases have avoided such practice because they truly fear being under the water in the boat.

As far as the rafting simile, if the panic is due to claustrophobia there is no parallel. I happen to be one of them - it took me forever just to calm down enough to execute a roll despite having a lot of water time including having to wait out being rolled under by waves body surfing when I was a kid. If you have not done this, one fairly common thing is to miss the best exit and have to ball up for a moment while the thing crashes you into the sand.

I found out as an adult in a kayak surfing class that I am still fine being thrown around in waves. In fact the day they were really too big for beginners to learn on I was having far too good a time ending up in the water. I had to pull it in and stay closer to shore to focus on the work at hand. I have been in the drink in class 2 white water and found it almost as much fun, except that having to worry about getting caught behind a rock or branch was a pain in the neck compared to being in big open water.

What I could not manage without a ton of work - work that still has to be repeated every time I have to go back and recover my roll - is staying calm with my legs in the boat rather than swimming free. It is an entirely different problem than just being under water.

Sorry Pete - I wasnā€™t clearā€¦ what I meant was that there would be evolutionary pressure favoring the ability to have at least some gasp reflex control if given at least that millisecondā€™s warning. People have been falling through ice for tens of thousands of years - mostly feet first, Iā€™d think. Those that survived to reproduce most would have been those that didnā€™t drown from gasp reflex.

I sure donā€™t doubt that there is a gasp reflex and Iā€™ve read about it often enoughā€¦ Iā€™m not convinced that it wasnā€™t a factor in the loss of a common friend of ours, in fact. But its the difference in how the particular sequence of immersion affects the gasp reflex that I havenā€™t seen so much about and that is a matter of curiosity to me.

In a dry suit or dry top, in a kayak with a skirt, of course a quick immersion of the head in ice water isnā€™t likely to cause a gasp reflex that could lead to drowning. Its been done a million times. (But I think its a lot more likely to trigger a gasp reflex rolling a kayak than by, say, stepping through ice into knee deep ice water, assuming equal percentages of the body wetted.)
I was thinking of complete immersion situations and the order that the parts of the body were subjected to that immersion.

The gasp reflex is most commonly triggered by whole body sudden immersion in cold water, not necessarily just the head. Where it can be deadly is if your head is under water when it happens. You can also lose control of your breathing and may hyperventilate for several minutes. Again this can be deadly in rough water, especially with no PFD to help keep your head above water. The gasp reflex can be triggered in water as warm as 60Ā°F.

With clothing suitable for immersion and the water temperature you greatly reduce the chance of suffering from the gasp reflex. Cold water is prevented or greatly slowed from affecting the body all at once.

A less common issue with your head submerged in cold water is that some people suffer extreme vertigo when cold water floods the ear canal. This can prevent a successful roll or even a wet exit.

Wouldnā€™t a well fitted neoprene hood prevent water in the ears if underwater briefly? I windsurfed winters in NYC with a full winter wetsuit and never remember getting water in my ears but that was long ago.

Yes it would. Thatā€™s a good reason. besides just keeping warm to wear one. It will also slow the water from reaching your ears to allow it to warm a bit first.

It helps but it can be problematical for whitewater boaters. Even a thin hoodie usually requires the boater to have two different size helmets. Some helmets have a moderate degree of adjustability for size but often using a neoprene hood requires a completely different shell size.

There are some pretty decent ear plugs that prevent water entry all the way into the auditory canal and still allow for some ability to hear. I know some whitewater paddlers who use them.

Although a gasp reflex response may be elicited by immersion of the body exclusive of the head in cold water, research has indicated very clearly that immersion of the face is most likely to elicit the response. The cutaneous thermoreceptors are distributed with moderate density throughout the skin of the body, they are distributed with very high spatial density in the facial region including not only facial skin but the corneas, lips, and tongue.