I am doing a hike in January in the Smoky Mountains. Average lows are in the twenties. I have a sleeping bag that is rated to 32 degrees, a Montbell down jacket, and a down vest. Should I rely on my clothing to keep me warm, or add another bag to add to the warmth of my first bag. Comfort is definitly more of a concern than weight. Any help would be awesome!

Jonathan-

Bringing a 32 degree bag down into the twenties with insulated clothing is pretty routinely done by a lot of bpl readers. There are a few caveats, though:

1) Don't skimp on your sleeping pad. Especially if you are on snow, a full-length pad of R-3 or greater insulation can make the difference when you are pushing your sleep system to its warmth limit. (Although, amazingly to me, some SUL fanatics seem to be able to get by with barely a kidney-sized piece of bubble wrap...)

2) All of the insulation you mentioned appears to be focused on your torso. Don't forget your extremities. You might be able to wear the Montbell jacket and use the vest somehow over your legs. (Experiment to see if this will work for you.) Still, when wearing insulated clothing inside a sleeping bag, the airspace between the clothing and bag interior will be cooler than it would be without the insulated clothing. This means that you have to pay particular attention to keep uncovered extremities warm. Insulating your torso only can make your head, hands and feet colder unless they are also insulated.

3) Be sure to try a backyard experiment, or overnight trip with a bailout plan before you take a new sleep system into remote cold conditions. In addition to the usual disclaimers about metabolism, conditions, experience, etc., you didn't mention the warmth of your jacket or vest, so it's impossible to say if your bag+vest+jacket will be sufficiently warm for *you* in the conditions you expect.

Good Luck!

-Mike

Edited by MikeMartin on 12/19/2006 16:54:20 MST.

The question also arises about where in the park you are hiking. If you are in the valleys, 20's at night are a safe bet. If you're hiking the AT or the Mt. Leconte area, plan for night temps that can be well below (due to being almost 5000 ft higher than the surrounding valleys). Night time temps are as likely to be 0F as 25 in January.

One more point that might help out. Perhaps you already know this, perhaps not. But if you wear your down jacket inside your bag, you'll likely get little or no benefit from it because the loft will be collapsed from pressure points inside the bag. I've draped my down jacket over my bag in the past and had success in noticeably warming my sleeping bag. You might also be able to drape your vest over your legs for similar warmth.

I agree with Shawn. A 32F bag might be fine if the weather is ok. The lows over t-giving were only 20 at high elevation, but the vallies can be very cold due to the high humidity and catabatic(i think that's the right word) effect, and I've been there in March when it was only 5F. Check the weather before you go and decide from there. You can access the past weather data and area forecasts from the park's site.

Shawn writes:

>> But if you wear your down jacket inside your bag, you'll likely get little or no benefit from it because the loft will be collapsed from pressure points inside the bag.

Good point, Shawn! You either need a quilt, or a roomy enough bag so that neither the bag or jacket insulation is compressed.

Jonathan -- just out of curiosity, what kind of bag, jacket and vest are you planning on using?

Cheers,

-Mike

My current sleeping bag is the Mountain Hardwear Conness 32 (36oz), definitly not light by anyone's standards on this site. My Montbell jacket is the Alpine Light jacket that has 4 ounces of down, and my vest is from a non outdoor company, but rather a retailer( I used to work for a clothing store in the mall), but it does a good job of keeping me warm, yet again, not light by BPL standards. I won't be as high as LeConte or Clingman's Dome, and won't be in the valley, but rather somewhere in between. I doubt anyone that is not familiar with the Great Smoky Mountains National Park would know where I am going, but it is in the Elkmont area of the park. Highest elevation is around 3500 feet, I believe. I have a balaclava and fleece hat for my head, and have two pairs of baselayer pants that I am planning on wearing. For my sleeping pad, I have the 3/4 Ridgerest. What is a good option at keeping my feet warm? I read a little bit about using a vapor barrier for my feet, with this suffice? I am fairly new to lightweight backpacking, and I'm a college student, so funds are limited. I am in the process of trying to get some good deals on some light gear, so my gear collection is growing slowly as I am attempting to replace items that I bought before my conversion to light weight backpacking.

Here is a link to the weather data

http://www.nps.gov/grsm/planyourvisit/weather.htm

I'm not sure when another cold-front is coming through, but temps have been warm since the 1st of December. Looks like lots of rain is forecasted for Cherokee over the next week.

I often use a 20F bag with extra puffy clothing inside and it works well for me, but compression can be an issue if your bag is fitted well. Trying to buy new gear when you're in school is a total bummer, and the ability to buy it has been about the best part of graduating and getting a job again!

If you can, borrow a second sleeping pad-preferably inflatable & 3/4 length as it takes up less room- if the temperatures are going to be low. I find the extra insulation under me makes a very large difference for the weight.

Where in Elkmont are you headed? If you use VB socks I'd like to hear how they work for you.

My bag isn't that tight fitting, so it will allow for puffy clothing to be warn. I will be around Panther Creek in Elkmont.

>> What is a good option at keeping my feet warm? I read a little bit about using a vapor barrier for my feet, with this suffice? I am fairly new to lightweight backpacking, and I'm a college student, so funds are limited.

For a luxury item, I like the Possumdown socks sold here at BPL for sleeping. But, if you're on a budget and want to experiment with VBs on your feet, I've had good luck sleeping with large size Reynolds Oven bags on bare skin (or over a very thin liner sock) with wool hiking socks over them. Even cheaper are the plastic bags that sliced bread comes in.

Cheers,

-Mike

Edited by MikeMartin on 12/28/2006 00:38:23 MST.

Thanks a lot for all of the advice! I will post and let you know how my trip goes. Happy New Year and Happy Trails!

The trip went well. I ended up using another layer of merino wool socks and I was fine in my 32 degree bag, but I was jealous of my buddy's Western Mountaineering 0 degree bag. We had some unexpected river crossings that required us to put on our camp shoes and get knee deep in the water, but overall, great trip! Thanks again for the advice guys.