You know those disclaimers you see on ads, telling you these are professional stunt people and not to try it yourself. Well, in this case, I want you to get out and try it yourself.
It got cold last night. I know because I woke up in a frost-covered tipi this morning. It was 41 when we went to bed, 29 when we woke up, and I'd had a great night's sleep, warm and cozy and comfortable. "Not surprising," you say, "This nutcase goes out camping all the time and has all the right gear."
True (at least about the nutcase part), and normally I'd have had a sleeping bag rated to about 20 degrees for the expected conditions. But this time, my buddy David and I had deliberately chosen the wrong sleeping bags. We knew it was going to get cold, and we wanted to test two summer-weight sleeping bags for EasternSlopes.com to see how well they'd handle the cold.
David sleeps warmer than I do; he carried a new ultralight "Funas Lite" from Fjall Raven, which is rated to 57 degrees. I had an Ignite 40-degree-rated synthetic-filled bag from Kelty, the same bag I'd used comfortably at 43 degrees while kayak camping on Treat Island a couple of weeks ago.
But late October? With temps below freezing? Well, as they say, we may be crazy but we're not stupid ... we knew the bags were likely not warm enough for the projected overnight lows, so we went prepared. That way, we could see how well the sleeping bags worked in colder weather, and still be comfortable enough to get a good night's sleep.
As I said, it was 41 degrees outside when we snugged up the bags. I slept comfortably until about 2:30, when the temp had dropped to 30 -- well below the sleeping bag's rating. My feet (which are hard to keep warm in the best of circumstances) were just slightly chilled, not cold. I tossed a hand-warmer pack into the bottom of my bag and went back to sleep until it was time to get up.
In a bag really designed for warm summer nights, David had to be more proactive, eventually using an overbag, handwarmers and more clothes inside his sleeping bag. But he, too, slept comfortably warm.
More importantly, using only the stuff we normally carry with us at this time of year, we both felt we could have been comfortable had the temperature dropped to 20 degrees -- or even lower. Sure, having a sleeping bag with an "appropriate" temperature rating is really nice, but don't miss an opportunity to go camping in beautiful fall weather just because your sleeping bag isn't "warm enough." Life isn't a spectator sport. Get out and enjoy!
Six steps to sleeping warm
With these extras, you can easily add 15 or even 20 degrees to the rating of any bag.
Step 1: Make your bed. What goes under you is as important for warmth as your sleeping bag, especially when the ground is cold. My tipi has no floor, so I start with a heavy-duty space blanket large enough to wrap around my sleeping bag in extreme conditions. Next comes insulation, a full-length closed-cell foam pad (which doesn't absorb water ). If you need more comfort, add an insulated air mattress on top of the foam pad. Then lay out your sleeping bag and let the fill fluff up. If you have an overbag or a silk liner, either will add about five to 10 degrees to a sleeping bag's temperature rating.
Step 2: Clean and dry. If you want to sleep warm, it pays to wash just before bed to remove any residual salt on your skin. A quick wipe with a small square of pack towel dipped in warm water is enough.
Step 3: Dress for success. Whoever first propounded the myth that it's warmer to sleep naked inside a sleeping bag should be forced to do so as punishment. The stuff you wore during the day is probably clammy and possibly sweat soaked -- which is how the myth of "naked is warmer" probably got started. After you wash, put on a set of "silkweight" long underwear tops and bottoms that you keep just for sleeping, and a clean pair of wool socks. That way, you always have a clean, dry wicking layer next to your skin. Have a fleece beanie, or, better yet, a balaclava handy, along with more layers of socks, fleece and even gloves and a "puffy" jacket (perhaps with a hood) ready to throw on if needed.
Step 4: Fuel up. Be sure to eat hearty and drink often when you are camping out. You need to fuel the internal furnace to keep you warm all night. If you're dehydrated, you are going to be cold, so sip water right up until bedtime. Keep a snack and some water within easy reach all night.
Step 5: Add heat. In the olden days, we used to fill a water bottle with hot water, put it in a sock and stash it in the foot of the sleeping bag. Effective, but not comfy. Now we use the disposable handwarmers in the bottom of the sleeping bag in really cold weather.
Step 6: Breathe outside the bag. With a mummy bag, set the hood opening so it's over your nose and mouth so all the moisture from your breath goes out into the air, not into your sleeping bag. If your sleeping bag doesn't have a hood, don't be tempted to crawl deep inside the bag to stay warm. Instead, put on your hat or a jacket with a hood.