Extending temp. Range of sleeping bags

[Danehunter]

To keep my pack light I try to make items do a dual purpose whenever possible.

For extending the temperature range of my 20 F. Western Mountaineering Megalite sleeping bag I can wear my light down puffy jacket and medium weight polyester underwear along with a balaclava to cover my neck and most of my face. (BTW, my WM Megalite bag is cut larger in the torso so I have room for this extra insulation.)

Also I put my zipped up GTX or eVent parka over the foot of my sleeping bag. This also keeps tent wall frost from melting and wetting the foot of my warm bag.

And placing soft boughs beneath my tent floor gives more insulation, as does placing my pants and sweater beneath my mattress.

So what do you guys use to do extend bag warmth?

 

[Andy Backus]

Cold feet are usually the limiting factor for me as to how low of temps my bag will work in. This year I tried these down booties and was very happy with them. I could wear them around camp at night and in the morning as they have heavier duty nylon fabric on the bottom and some sort of simple foam insole. They are super ultra-light and packable. I was able to stick with my Big Agnes Lost Ranger 15 degree bag rather than hauling my BA Storm King 0 degree bag way back into the mountains.

The next step for me when it gets even colder is to wear my Sitka Kelvin Lite Pants (puffy pants) and down jacket inside my sleeping bag.

 

[Danehunter]

Andy,

I agree having a puffy jacket and pants is a great way to extend the comfort range of a sleeping bag. My synthetic mid layer insulation pants are DuPont Thermolite Micro and are very warm. They go under GTX or eVent pants for extreme cold weather or winter tree stand hunting.

Your doen booties are a "luxury" that can become a necessity once experienced. If the soles are too slippery you can get some Shoo Goo and put lines of thin ripples of it across the soles to give more "gription".

Right now I am getting ready to buy a pair of MontBell Tec down pants. They are a little over 6 oz. and at $145. a decent buy. Most quality down mid layer pants are over $200.

Currently my cold weather hunting/BC skiing pants are a pair of Duluth Trading Dry on the Fly fleece lined nylon cargo pants. I can usually get down to 10 F. with them and a pair of medium polyester long johns.

Eric B.

 

[ssssnake529]

Wearing clothing inside your sleeping bag is a good way to extend the temperature range.

However, many (most?) sleeping bags are not cut full enough to take full advantage of this. A sleeping bag with a wider cut may weigh a bit more than a slimline bag, but it will allow for more clothing to be worn in the bag, making it the warmer (and lighter) option.

 

[Laelkhunter]

Buy several of the cheap "space blankets". They are thin aluminum foil material. I got several, and they were really cheap on ebay. I think they were listed as survival blankets, and three packs together are about as big as a deck of cards. Lay them on the floor of the tent, under your pad or sleeping bag. They will insulate from dampness and cold.

 

[Andy Backus]

Wearing clothing inside your sleeping bag is a good way to extend the temperature range.

However, many (most?) sleeping bags are not cut full enough to take full advantage of this. A sleeping bag with a wider cut may weigh a bit more than a slimline bag, but it will allow for more clothing to be worn in the bag, making it the warmer (and lighter) option.

That's one reason I like the Big Agnes system bags where they eliminate the down fill on the bottom of the bag to save weight and the bag is cut with more room resulting in a roomier bag that weighs the same as a similar mummy bag. I also move around as I sleep from my stomach to my side to my back and the roomier bag is the only way to go for that.

 

[fatski]

I have had good results using the Sea to Summit Thermolite® Reactor Extreme Liners to extend the range on my 20 degree Sierra designs sleeping bag while hunting elk this past september to october. That will also be the system I will be using down in Mexico while guiding the volcanoes this January.

 

[Len Backus]

My Big Agnes System bag model is the Mystic UL 15 which weighs 2.5 pounds in LONG size. As with Andy's BA system bag, the bottom has no weight devoted to insulation, instead relying on the pad.

I also adjust my clothing layers for temp comfort. I like the bivy idea

When I am on a solo DIY hunt, day hunt only, if I'm going to be pretty far back in, I'll carry a EMO brand lightweight syl fabric fly. I also carry an SOL Escape Lite bivy. When I googled fatski's liner idea I saw a Youtube video on it and the video poster's use of a similar SOL item as a liner. I like that idea since I already carry one often.

My fly and SOL bivy:

If stranded out there over night in an emergency I think I'd be ok with just the fly and SOL Lite bivy.

Together they only weigh 1.5 pounds. These days hiking or on hunts I almost always carry trekking poles. The carbon fiber Black Diamond Distance Z poles that weigh just 10 ounces. They would support the deployed fly if there were no trees.

 

[Danehunter]

I agree that you must have a bag large enough to accommodate extra clothing. My 3 season Western Mountaineering Megalite bag was designed just for that purpose.

My LL Bean -20 F. Down bag is also big enough to let me wear my light down Eddie Bauer jacket inside it.

I just sold an older Mountain Hardware synthetic -20 F. bag that had a full length zippered gore above and parallel to the main zipper. When unzipped this gore was 6 " wide and I could easily get my 3 season Megalite down bag inside without squeezing it.

Now that MH bag is owned by a guy in Minnesota where the Polar Vortex is hitting hard. He needs a bag like that!

Andy and Len, what mattress do you guys use with your BA bags?

Eric B.

 

[Len Backus]

Eric

Q-Core SLX from Big Agnes

 

[Danehunter]

Backus Bros.,

I really like that BA Q-Core mattress batter than my Thermarest Trail pro. Plus it's warmer. I may get one.

Last week I finally got my backordered LL Bean -20 F. bag with Down Tek DWR treatment on the down. At $26 9. on a double sale. It is a far better designed bag than the Eddie Bauer -20 Karakoram that I returned two years ago for its poorly designed "collar".

We have a lot of snow in our Spring Mountains north of the 'Vegas valleyso soon I'll be camping and backcountry skiing up there at 8,000 to 10,000 ft. in my "winterized" Tarptent Scarp 2 and the LL Bean -20 bag. No bugs and npc people. My kind of camping.

Eric B.

 

[RockyMtnMT]

I think I am going to be in the minority here but my understanding of how a sleeping bag works is a bit different. My understanding is that a sleeping bag reflects back your body heat and if you are not letting your body heat get to the bag it can not give it back. So to speak. So by wearing clothing in your bag you can get colder than not wearing anything because you are depriving the bag of the heat it needs to do its job. As my memory serves me this may differ on what type of fill the bag has. As I see it when you wear clothing in the bag, now the bag is enhancing the clothing's ability to keep you warm but in fact making the bag not as warm. One would be better off putting something around the outside of the bag to help the bag hold in heat.

One thing that I do know is that the temp rating on bags is not a comfort rating it is a survival rating. Meaning you can make it down to 20deg in a 20deg bag but not comfortably.

Steve

 

[Danehunter]

RockyMT,

A sleeping bag reflects back very little of your body heat. Instead the insulation TRAPS warmed air (and body moisture) and slows the transfer of heat outward.

A sleeping bag will have a scientifically tested R Value (thermal insulating value, just like home insulation).

Wearing more clothing, especially insulating clothing like fleece, synthetic fiber insulation, down insulation or even plain street clothes will add warmth to any sleeping bag or sleeping quilt.

Tha best location for a reflector of body heat ("space blanket", mylar sheet, etc.) is under your mattress, where it keeps you warmer even though the insulation beneath you is compressed by body weight.

Eric B.

 

[RockyMtnMT]

RockyMT,

A sleeping bag reflects back very little of your body heat. Instead the insulation TRAPS warmed air (and body moisture) and slows the transfer of heat outward.

A sleeping bag will have a scientifically tested R Value (thermal insulating value, just like home insulation).

Wearing more clothing, especially insulating clothing like fleece, synthetic fiber insulation, down insulation or even plain street clothes will add warmth to any sleeping bag or sleeping quilt.

Tha best location for a reflector of body heat ("space blanket", mylar sheet, etc.) is under your mattress, where it keeps you warmer even though the insulation beneath you is compressed by body weight.

Eric B.

I did a quick check with REI and they recommend sleeping with light dry clothing. They warn against wearing too much clothing as it will inhibit the bag from doing its job. Staying dry and starting the night out dry seems to be one consensus that I can find. Along with a very good pad to insulate on the side that you laying on.

Other than that there is differing opinions on this subject.

Steve