Don't drink (alcohol) the night before, and bring the right food.
Bring the right food.
Bring twice as much as you think you need as well.
I crashed at 2am starving hungry and went hypothermic because my gear was soaking and I didn't have a dry insulating layer to add.
I did however bring my nasty wool survival blanket and a change of socks+ underwear so I was able to dump my gear and raise my temperature back to acceptable levels.
If you're a sweaty guy like me you need to bring a fleece or a wool undershirt so that you can retain some heat while soaking.
You think that if you just keep going the cold sitting next to your skin won't affect you, but it will. Especially if you don't have any fuel to burn.
Allowing myself to get that cold and that wet was stupid and irresponsible. I should know better. Luckily I know what hypothermia feels like, what it does, and how to avoid the delusional side-effects of it, so I was not in any danger.
What being extremely cold and hungry did do was take me out of the game and leave my team hanging.
Don't do that.