Okay, I’ve been promising a geek post about my sleeping bag. Here goes…
My sleeping bag is probably the single most important and hard-to-replace piece of equipment I carry with me. Maybe second to my boots, but a close second nonetheless. Something could happen to pretty much any other piece of equipment I carry with me, even my tent or backpack. But if something happened to my sleeping bag, I don’t know what I’d do.
When I say "sleeping bag" I actually mean two things. The first is the sleeping bag itself. The second is a bivvy (bivouac) sack I keep slipped over the bag.
I bought both items from REI in 1996.
The bag is an REI house-brand down bag rated to minus 20 degrees Fahrenheit (minus 30 degrees Celsius).
The bivvy sack is made of Gore-tex by OR (Outdoor Research). The bivvy sack is shaped like a sleeping bag and slips over the sleeping bag itself.
In the summertime I sleep on top of the sleeping bag, without using the bivvy sack at all. In the spring and fall I have problems with sweating inside the sleeping bag, because it’s too cold to sleep on top of it, but at that point the bag is too warm to get inside without sweating.
Last night, however, the temperature hovered between freezing and 34 degrees Fahrenheit (0 and 1 degree Celsius). When the temperature hits freezing or below, the sleeping bag really starts to work its magic. I was snug as a bug in a rug last night, sleeping 6 hours without waking up even once, not sweating at all, it was great.
I may only sleep for about 6 solid core hours, but I’m in the bag for 10 hours or so — when it’s winter, the days are short, and I don’t have much to do when I’m not walking or talking to people. So I just hang out in the sleeping bag after dark, even if it’s only 6:30pm.
The bivvy sack is important because it keeps the sleeping bag dry. If the sleeping bag gets wet, it’s virtually worthless. Sometimes condensation drips down from the roof of the tent, like it did this morning, or sometimes the night starts out clear and I don’t put on the tent’s rain fly, but then the weather turns and starts raining during the night. Or, in the past there have been times I didn’t use a tent at all, and it rained directly onto the bivvy sack. In any of those cases, the bivvy sack keeps the sleeping bag dry. And remember, a wet down sleeping bag is a virtually worthless sleeping bag.
I used to use this combo (this sleeping bag and the bivvy sack) to sleep on the snow. Not near the snow, actually on it, with no tent. Just tamp down a flat place on the snow, throw down the bag/bivvy, insert the Thermarest air pad, and go to sleep.
When I mention to Turks along the walk where I’m going, they often comment on the weather, and warn me how cold it’s going to get. I tell them I have a warm sleeping bag setup, but they look at me like they don’t believe me. I suspect they don’t understand just how warm this sleeping bag is. Maybe I’ll find out later they’re right and I’m wrong, but it’s going to have to get pretty cold before this setup stops working. I’ve tested it for years in snow, wind, ice, you name it, and it’s never done me wrong. I guess we’ll see.