I think I've landed on this as my method if I ever choose to die, but there is limited information on real cases of suicide by hypothermia. What is the success rate assuming you don't change your mind halfway through?
Any other tips for higher success besides fasting, sleep deprivation, and alcohol?
Lots of people have died of hypothermia, so plenty is known about it, even though it doesn't seem to be widely used as a method of suicide.
It's the way I will go when my time comes. I have known that since I was a teenager. I spent a lot of time in the oudoors when I was younger, and I would just head off into the wilds, alone, in cold weather,, and not come back If the temperature is well below freezing, the one thing you
must avoid is failing to die and waking up with frostbite. However, you can die - and die quite quickly - at temperatures a little above freezing, especially if it is wet, and even more so if it is wet and windy, and of course there is then no possibility of frostbite. You need to do it somewhere you won't be found until you are well and truly dead. (I will try to ensure that I am never found at all.) So although it might be possible to do it in your own neighborhood, that may not be a good choice. (People have died, accidentally, of hypothermia outside their own front door.) It needs to be planned properly, but I don't think it's particularly difficult. It's a peaceful way to go. Obviously you feel cold for a while, but as your body temperature falls further, you eventually feel nice and warm and comfortable. And then there is nothing,
Alcohol interferes with the body's temperature regulation, and can make hypothermia happen faster. I won't be using it. Seems to me that if I can't ctb without alcohol, then I probably shouldn't be doing it at all. But you may feel differently. Tranquilisers are another possibility (though I don't plan on using them either).
Sleep deprivation is irrelevant, you don't need it, and it might interfere with your ability to manage the situation.
Fasting will, in theory, make you more vulnerable to the cold, but I think the effect would be small unless you have fasted for a long time. (In my case, fasting would be counter-productive, as I will need enough strength to get well out into the wilderness.)
As for changing your mind halfway through, I won't be able to, because I will have gone too far out in the wilds to be able to return. But if you are somewhere closer to "civilization" you will probably be able to to reverse things while you are still at the stage of simply feeling a bit cold. When it gets much beyond that, you won't. The boundary between between able to reverse things and being unable is probably very fuzzy, and inability to function effectively will creep up on you stealthily, so if you are in any doubt about wanting to ctb, don't want too long before changing your mind.
Hope that helps.
endorfeen.com
www.bbc.co.uk
sanctioned-suicide.net
I was shivering a lot but it wasn't unpleasant or painful. I understand shivering stops once you enter moderate hypothermia. 
