Keep at least one water bottle in the sleeping bag, if it will fit and not leak. If you can’t, put it under your bag at the knees. All other water bottles that don’t fit under your knees could be put in some of your extra wool socks. Also, heat the water up at night before you go to bed and put the filled bottles in your sleeping bag as you fulfill your nightly duties. Then when you get to bed, your bag will actually be warm.
Don’t forget the nightly duties. A full bladder requires more heat than an empty one, plus getting up at 2:00 AM in sub-zero weather is absolutely no fun.
Carry and store water bottles upside down. Ice forms on the tops of bodies of water first, so this helps keep ice from forming around the mouth. If you’re not carrying a water bottle, stick it in a spare sock or shove it in a snow bank, upside down, of course. Snow will insulate better than nothing.
If you’ve got a self-inflating mattress don’t roll it up with the valves closed. A frozen mattress valve is real hard to open.
When standing around eating, cooking, or whatever, stand on your mattress pad. When sitting, sit on your pad.
Keep active as much as possible. If you feel your feet freezing up, start getting the shakes, or if you see anybody else showing initial signs of hypothermia - go for a long, brisk walk/jog. Take the whole troop with you, because they may be feeling the same way, but are too "cool" (there’s that pun again) to show it. Keep going until the signs go away.
Go for a night hike or play an active game just before you crawl in the bag. After you get in the bag, take a mouthful of water and eat something fatty like cookies. This gets the furnace started and helps keep it going throughout the night.
The standard 3-tub method of doing the dishes just doesn’t work in the extreme cold. Heat up some water and pour this in individual bowls to melt the leftover bits and pieces of food. Soak your utensils in this. Then use a paper towel or even a snowball to scrub. Any cloth dishrag will freeze.
Bring extra everything. Stoves and lanterns will fail. Water bottles will freeze and crack. Things, like boys, just behave differently in the cold.
Everyone on the trip should know the signs and treatment of hypothermia!!!
To keep boots from freezing up overnight, lie them on their sides beneath your sleeping bag under your butt with the soles sticking out. Put one on each side of you and tie the laces together with a simple knot. There should be enough heat escaping there to keep the frost out, plus the placement will help keep you from rolling of your mat.
Keep gloves, socks, and any of tomorrow’s clothes as will comfortably fit inside the sleeping bag. Any other clothes, jacket, sweater, whatever doesn’t fit, should be put under the bag. It’s much more comfortable to dress in pre-heated clothes and the added insulation doesn’t hurt.