A sleeping bag that kept you warm in July can leave you awake at 3 a.m. in October, and often the bag is not the problem. The cold ground pulls heat out of you all night, so the pad underneath matters as much as the bag on top.
It is written for nights near or below freezing, on a fall car-camping trip or a short backpacking trip. It assumes you already own the usual camping gear and covers what changes when it gets cold. Camping on snow in deep winter needs more than this list.
Pad warmth is rated by R-value, and R-values add together. A cheap closed-cell foam pad under the inflatable pad you already own is often enough to make a freezing night comfortable.
- Check the forecast low for the campsite itself, not the nearest town — Higher sites and valley floors can be much colder overnight.
- Check the campground is still open and what has been shut for the season — Many seasonal campgrounds close in fall, and some that stay open turn off the water.
- Find out whether hunting season is open where you are going — If it is, wear blaze orange on the trails and put some on your dog.
- Tell someone your route and when you expect to be back
- Plan to reach camp at least an hour before sunset — Fall days are short, and pitching a tent with cold hands in the dark is slow.
- Compare your sleeping bag's comfort rating with the forecast low — The lower limit rating is a temperature you get through curled up, not one you sleep well at.
- Check the R-value of your sleeping pad — For nights near freezing, aim for a combined R-value of about 4 or more. Stack a foam pad under your usual one to get there.
- Pack wool or synthetic base layers, not cotton — Cotton holds sweat and stops keeping you warm once it is damp.
- Pack an insulated jacket to wear around camp
- Pack a separate dry set of base layers and socks for sleeping
- Pack a warm hat and two pairs of gloves — One pair will get wet setting up camp.
- Pack lithium batteries for your headlamp — Alkaline batteries lose power quickly in the cold.
- Check that your stove works in the cold — Gas canisters lose pressure near freezing. Keep the canister in your jacket before cooking, or bring a liquid fuel stove.
- Pack more fuel than you would in summer — Cold water takes longer to boil, and you will want more hot drinks.
- Keep your water filter from freezing — Ice inside a hollow-fiber filter can damage it with no visible sign, and a damaged filter may let germs through. Put it in a bag at the foot of your sleeping bag at night.
- Store water bottles upside down overnight — Ice forms at the top first, so the lid end stays clear.
- Pitch the tent out of the wind and away from hollows — Cold air settles in low ground overnight.
- Leave the tent vents partly open at night — Your breath condenses on the walls and can drip or freeze onto the bag.
- Never run a stove, heater or grill inside the tent — They give off carbon monoxide, which builds up in a small closed space with no warning.
- Eat a hot meal with some fat in it before bed
- Change into your dry sleep clothes before getting into the bag
- Put a bottle of hot water in your sleeping bag — Use a hard bottle rated for boiling water, check the lid seals, and wrap it in a sock.
- Keep your phone and spare batteries inside the sleeping bag
- Go to the toilet before you settle in — Leaving a warm bag at 2 a.m. costs you far more heat than going now.
- Know the signs of hypothermia — Watch for hard shivering, fumbling hands, slurred speech and confusion. Get the person dry, out of the wind and into warm layers, and get help if they do not improve.
- Dry the tent and sleeping bag fully once you are home — Gear packed away damp grows mildew.