“How to Increase Sleeping Bag Warmth – Tips and Tricks” – Source: viasuecia.com

Via Suecia is a digital trail through the lenght of Sweden between Smygehuk in the south and Treriksröset in the very north. It is 2 643,3 km in lenght. (viasuecia.com)

How to Increase Sleeping Bag Warmth – Tips and Tricks

1. Adjust your feathers and down. Some bags have continuous baffles meaning you can
   shuffle the down to the chest area to get you warmer.
2. Add a liner. This might increase the warmth of your bag with several degrees
   depending on material and thickness. It also keeps your bag clean meaning a warmer
   bag.
3. Add a VBL (a vapor barrier liner), i.e., a WM Hot Sac. It works by stopping heat loss
   from evaporative cooling. A VBL will also prevent your body vapor from degrading
   your insulation and by stopping radiant heat loss with its reflective metal coating. An
   emergency hypothermia bag can also do the trick. Put it inside your bag.
4. Down booties. Yummy! Western Mountaineering Flash Down Booties are only 85g
   for a pair in Medium. There are other brands, too.
5. Increase and improve your ground isolation. If you’re only using a basic sleeping pad,
   try an insulated one. There are a few to choose from, I use an Exped DownMat with
   integrated pump.
6. Use double pads as mentioned above.
7. Wear some long wool underwear, i.e. Try not sleeping in the clothes you use during
   the day.
8. Air out your sleeping bag every morning. Flip it inside out in the tent. The moisture
   created during the night get a chance to air out this way.
9. Crank your metabolism! Eat some warm high-energy food before sleeping. This
   energy is what creates warmth in your body and keeps you warm during the night.
   Think of yourself as a stove. Food = fuel.
10. Use only dedicated dry sleeping clothes. Keep them in a drybag.
11. Do some push ups or jumping jacks before you go to bed.
12. Open your bag early. Let the feathers and down re-loft and decompress. Lap your bag
    around you while cooking food or warming water in the tent. It will also keep you
    warm and be not so cold when you creep into it.
13. Use a hot water bottle to pre-heat your bag. If used during the night, use it inside a
    waterproof bag to avoid any leaks. Nalgene is a brand that handles boiling water.
14. Pee before going to bed.
15. Wear a buff, hat or beanie. You might lose up to 20% of your heat through your head.
16. Wear fresh wool socks. Not your sweaty daily socks.
17. Wear less clothes! It does not make sense but that’s the way it is. To much clothing
    will make you cold. So, sleep near naked.
18. Use your down jacket on the bag, over your feet or chest. Nothing heavy.
19. If you fail to plan, you plan to fail.

From www.viasuecia.com