Although many of those medical terms are over my head, this is a very informative thread. Hopefully this one will continue on so that people can become more familiar with combating the "effects" of a cold water swim.
I may be setting myself up for some involuntary laughs, but two weeks ago we flipped in the lower section of the Lochsa at Hellgate rapid. I will admit that I made the mistake of think this was the "beer drinking section" although we weren't drinking, and did not realize how big this rapid was.
Admittedly, over the last 5-6 years I have put on 30 lbs and had recently given up another habit. No excuses, but it happened. The last time I've been in a boat that flipped was 8 years ago and I was in nearly tip top shape and the cold water did not have any adverse effects on me.
This time though, I was tired, out of breath, had a pulsing head just from the short swim and had a hell of a time pulling myself on the raft. Kind of a rude awakening, but I've already made provision to not be that wiped out again and not be able to self rescue.
I am a firm believer (now) that if you think you're going to take a swim in the earlier part of the season, you had better be in relatively decent physical and cardio shape. I truly believe that had I not mustered the last bit of strength to pull myself up, I would have possibly succumbed to the water, more from exhaustion than the cold. Although I know the cold water was a big contributor to my exhaustion.
Now with that long winded comment out of the way, I do have a few questions to help myself understand more and to keep the discussion going:
On the other hand, dry drowning is a completely different process. Dry drowning involves water reaching the larynx, which results in a spasm that closes the lungs to water. The lungs don't fill with water and the victim suffers a heart attack from the lack of oxygen to the heart muscles.
This statement (sort of) makes sense but......Is it just a quick spasm that goes away or does it linger like a charlie horse can? Does the larynx not open back up. I would have to assume that it stays closed because 15 seconds would not be enough to cause lack of oxygen to the brain..?..
What about when someone takes a nice really cold drink of ice water or takes an overly large bite of ice cream? That water is just as cold, if not colder than even spring run off. Is there that much more water reaching the Larynx than a large glass of something cold purposely going down the throat.
One thing that I learned in a Swift Water class was that when you initially get dumped in very cold water it is very important to exhale a first deep breath which I believe helps to keep the lungs working. I haven't done any research on this but do believe it helps cause I sure do practically "lock up" with the initial shock of the water which I think could result in cardiac arrest if I wasn't in shape and relatively young?
If you let out a big exhale in anticipation of the immersion, wouldn't you naturally want to inhale that much more readily in the event of hitting that really cold water, which would more likely cause an ingestion of water?
Great discussion so far....