A bit of an update about the cold water thing. I don't think people understand the severity of it, as demonstrated to me not long ago. A while ago I went into extremely cold water with some friends and they couldn't understand how the water was that bad until I explained it as such:
It felt as though all the muscles and my skin in my feet were ripped apart and bleeding. My ankles felt as if they had just been bent backword. All the bones in my feet and ankles felt chilled and frozen down deep into the marrow, like my bones were replaced with ice completely. My shins were numbed and painful. It felt as though I had fell on my knees and scrapped, bruised and turned in more than usual. I won't go on with more details, but I hope you see how painful it is on top of dealing with the temperature.