Ain’t spring paddling in the north a blast! Just when you though you had the drowing aspect covered, along comes the cold water drowing aspect.
Cold water immersion leads to hypothermia, which eventually shuts down the extremeties while keeping the (relatively) warm blood in the body’s core. In ice out conditions without wetsuit or drysuit, it starts to make a serious impact after a couple of minutes. As coordination is lost, the ability to self rescue or even assist in being rescued (e.g. hold a rope or the nose of a boat) is also lost. This makes immediate rescue imperative.
In less severe conditions, for example a rainy spring day, the mental process tends to deteriorate over time to the point that people become walking zombies who can’t think to help themselves and sometimes refuse assistance from others.
For mild hypothermia (shivering or shivering until recently) external warmth and sugar based warm drinks do the trick, but for serious hypothermia (e.g. thoroughly passed out with cold for quite some time) it is important to not try to attempt rewarming or to jiggle the person for a sudden surge of cold blood from the extremities could cause heart failue.
The best way to avoid hypothermia is to dress appropriately and keep an eye on each other with frequent spot checks. Aside from shivering, watch for slurred speech, lack of cooordination, and general stupidity. The best way I can describe the feeling of moderate hypothermia is that physically it feels like you are very tired and slow moving, while mentally it is almost like being in a a dream or like waking up very groggy.
Just to make things interesting, there is also something called the mammalian dive reflex, which kicks in immediately on some people (particularly young folks) when they pop their head under very cold water. Essentially everything shuts down as blood is directed to the heart and brain – almost like a sudden paralytic seizure. This can be very problematic, for just when you need the person to cooperate in their own rescue prior to hypothermia becomming a problem, you find that they are unable to move and sometimes even unable to breathe. The best way I can describe the feeling is that it is like a nightmare in which you are lying in front of a car or train which is about to run you down, but there is absolutely nothing you can do to move. The first few times this happened to me I was very scared, for not being able to move while being swept down a river with bergy bits can be a bit unnerving, but eventually I learned to calm down by forcing myself to recall that after about a minute I would be able to move again.
In ice out conditions the combination of dive reflex (the first minute or so) followed by hypothermia (affecting coordination after a couple of minutes) makes the window for rescue quite narrow. This is not that big a deal for experienced, practiced and attentive paddling teams, but unfortunatley is a bit much for most recreational paddlers, who simply are not able to respond quickly and efficiently enough. In short, unless your crew is up to it, wait for warmer water in the season – every degree counts – you would be astounded at the difference between swimming in 1 degree water or swimming in 5 degree water. The window for rescue in the first is very narrow, whereas the window for rescue in the second is somewhat limited, but not anywhere near as narrow.
Yes there have been extraordinary examples of people (particularly children) who due to dive reflex and hypothermia have survived lenghty drowning – essentially the body slows down and blood is directed to the critical areas such as the brain. The flip side of the coin is that an awful lot of folks simply have heart attacks and die when they fall in ice water (although I’ve only witnessed this once).
For folks who have the misfortune to fall into ice water, try to keep your mouth shut, your head tucked to your shoulder, and your face pointing away from the water when you fall in. This can help reduce the effect of the dive reflex (whatever you do, don’t take the cold water shot at the back of your open mouth – this seems to be a trigger point even more than the face). Then swim like the devil for shore with everything you have. Don’t wait a second to collect your wits. Just go for it and do not slow down. This will help you get back to land before you lose coordination (and even will power) from hypothermia, and the heat generated from your effort will buy you some time. Finally, if someone gets a rope to you, wind it around your arm as many times as you can, so that as you lose your ability to function, you don’t drift away.