Re: [Paddlewise] Cold Water Gasp

In a message dated 11/15/01 9:45:31 AM Pacific Standard Time, 
cholst_at_bitstream.net writes:

Chuck wrote:
> 
>  In those cases where people have gasped underwater and inhaled water, I 
>  suggest that surprise may have been as big a factor as water temperature. 
In 
> 
>  situations where the person is mentally prepared, I suggest that an 
>  underwater gasp is rare or nonexistent. By mental preparation, I mean that 
>  the person has chosen to immerse himself or herself in cold water, or is 
>  accustomed to it. 

and Matt:

>>It is my understanding that the folks most likely to be affected by cold
water shock mare those whose torsos are exposed enough to experience a very
sudden decrease in skin temperature there and those who may have lost their
ability to control the gasp reflex when underwater due to the effects of
drinking alcohol on the nervous system. I'm guessing alcohol's effect of
dilating the blood vessels near the skin might also increase the magnitude
of the "shock" experienced during cold water shock.<<


In Wayne Horodowich's new and very excellent videos on Kayak re-entries and 
rescues (http://www.useakayak.org/) there is a segment of video shot during 
testing of cold water effects.  A trained and experienced Navy(?) diver, 
dressed in a swim suit and breathing through a typical diving mouthpiece, is 
strapped in a chair.  He is slowly lowered into water at (IFIRC) 50 F.  He 
looks calm and collected until the water hits his head, then he starts 
gasping uncontrollably in the mouthpiece.  I'm sure he was mentally prepared. 
 What he wasn't was dressed for immersion.  The effect is real, and deadly -- 
just not universal.

Harold
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