23 Essential Winter Camping Hacks
4. Use hand warmers to warm up your sleeping bag.
If you’re in super-low temperatures, your sleeping bag relies on your body as its only heat source. With a hand or sleeping bag warmer, you can warm up the sleeping bag much faster while trapping in the heat.
You can also use them to warm up your boots before you put them on.
They’re $10.35 from Amazon.