I went to a presentation last night put on by the Mountaineers and presented by John Morton that had a lot of really good info on prevention of cold weather issues.
If John Morton is ever putting on a class while you’re in Seattle I would suggest taking it (and he puts on a lot of classes it sounds like, with a huge range of outdoor safety knowledge).
Some of the takeaway points I learned from this free class are below.
The body temperature numbers don’t matter because you won’t be able to read those numbers anyway, so look for symptoms. When the shivering stops and there’s a change of consciousness you’ve crossed a threshold. They will next have slowed breathing and heart rate. Once they’re to that point there’s nothing you can do outside of a hospital to save them, even if you can warm them up. So consider it an emergency way before then, because it is.
Before you even get to that stage of hypothermia you may be killed by other cold related issues.
Cold shock happens as soon as you hit the water and can kill in less than 10 minutes. If you survive that you can have cold incapacitation in under 30 minutes when you have swimming failure.
In the first minute there’s a gasp reflex (so wear your life jacket and keep your face out of the water / waves) and hyperventilation. Stay calm and get your breathing under control; it will pass. In the first 10 minutes do anything physical you can / need to while your muscles still work (including getting your personal locator beacon to work). Get your body as much out of the water as possible to keep your muscles working as long as possible. Once your muscles stop working you can’t help yourself, but you can wait for help. Even when you lose consciousness to hypothermia at around an hour you may still be rescued if you’re staying afloat with your life jacket.
How to prolonge your time and up your odds:
Wear your PFD, not just keep it on your boat.
Practice your techniques until it’s natural in similar conditions to what you paddle in, because once your brain is panicking you can only go off instinct and muscle memory. This includes activating that personal locator beacon and using your paddle floats for re entry.
Wear a Gortex dry suit in the puget sound. I wear a wet suit because I even hate soft turtle necks, plus their expensive, but this instructor provided a solution for the neck. At scuba shops they sell rings that go loosely around your neck that you can tuck the turtle neck part into while you’re not in the water. This keeps it from being constricting. Another tip he gave is to wear long sleeves under to keep yourself cool. This sounds counterintuitive but it has to do with how the dry suit breaths (how the water vapor passes through the gortex). If you get biker sleeves you can take them off when you land to have shorts and a t-shirt for the wonderful beach you paddled to for a picnic.
There was a lot more to the course and I recommend going to a similar course. What you learn now can save you on the water when you’re not able to google 😊