Found this nice article about keeping warm at night by Section Hiker.
This article was taken from the web site "Section Hiker". You can view the entire article here http://sectionhiker.com/the-art-of-s...warm-at-night/.

Have you even spent a cold night in your sleeping bag because the temperature dropped lower than you expected? Here are a few tips and tricks you can use to increase your comfort level on those cold nights without buying any additional backpacking gear.

  • Cover your collar bones with an insulated jacket or fleece sweater to prevent hot air from escaping from your sleeping bag when you move around at night. This is often the ONLY thing I need to do to sleep warmer at night.
  • If you sleep on an inflatable sleeping pad like a Therm-a-Rest NeoAir Sleeping pad, lie flat on your back, not on your side. Your back will heat up the sleeping pad and keep it warm better than your side because more surface area is in contact with the pad.
  • Wear a buff over your neck. This will keep you warmer at night and on cool days because it will insulate your neck and the veins that flow close to the surface of your skin.
  • Wear a fleece hat, even if your sleeping bag has a mummy hood. Your head radiates a lot of body heat because so much blood flows to your brain.
  • Wear your clothes inside your sleeping bag or under your quilt. I always bring long underwear top of bottom on trips for this purpose, and it keeps the inside of your bag cleaner on multi-day trips.
  • Shield your sleeping bag from the wind if you’re camping under a tarp and the walls don’t reach all the way to the ground.
  • Boil some water and pour it into a Nalgene bottle or water reservoir. Place the bottle or reservoir between your legs over your femoral arteries where they flow close to your skin. This will heat up your blood and make you warmer.
  • Stuff all of your speare clothing into your sleeping bag with you. By filling up the space, your body has less work to do to heat up the insulation.
  • Eat some fatty food like a candy bar before you go to bed. Your digestion will generate heat to make your warm.
  • Stay hydrated. You digestion will work better if it has enough water to digest your food.

What other tricks do you have for staying warm on cold nights?