Extreme cold weather sleeping bag

I just signed up for a Winter Emergency Medical Course for the last week of February in NH. My sleeping bag is rated for 15* F, and I'll bet the weather will be colder than that. What options do I have so that I don't have to buy another sleeping bag?

Here is an option: Sea to Summit Reactor

However, you may want more warmth than this will provide. If your going to be living out of your backpack, I'd search for a deal on a new -15 degree bag (from a good manufacturer). I have had good luck with north face (but add 5-10 degrees to there rating) mountain hardware (rating is right on!) and REI (warmer than rated by 5 degrees or so). Before I invested in my mountain hardware system, I had a 15 degree bag and a 32 degree bag that fit over my 15 degree... that coupled with a goot pad and a bivy sack kept me warm to -20 in the open and -45 in snow. It was a good system that gave me options for all conditions I encountered.

I have one of these for emergencies, and lent it to a member of my rescue squad durning a drill. She had a cheaper 30 degree bag that wasn't cutting it for the 25 degree temp, we placed the Thermo-Lite bivy over her bag and she was comfortable for the night.

I agree with Romania's suggestions of a sleeping pad and the Thermo-Lite bivy sack. I have used a Thermarest pad for over ten years. It has kept me warm and comfortable on some rough and cold ground. I haven't used the bivy sack as an overbag, but the theory speaks fot itself.

If you want to avoid the expense of buying a new bag, you could add a fleece liner to your existing bag. Wearing polypro or wool long underwear inside the bag will also help. Finally, try wearing a fleece or wool hat when you sleep. My wife does this and swears by it.

Good luck,

Steve

"Finally, try wearing a fleece or wool hat when you sleep. My wife does this and swears by it."

Indeedy. For $5, it's hard to beat the wool watch cap available at nearly any surplus store.

A good thermarest pad, like a Prolite 4 is going to help a lot for starters. As for the bag, if you want to keep your existing 15 degree bag, you could add an overbag to stay comfortable at far lower temps. The FTRSS (Flexible Temperature Range Sleeping System) overbag that Wiggy's sells as part of the military 3-in-1 system is large enough to contain a normal mummy style bag without compressing the insulation. They are very durable, can get wet and still insulate, etc.

(Wiggy's makes a -60 degree bag!)
http://wiggys.com/category.cfm?Category=6

You might look into renting a warmer bag for the course. If you are not living out of a pack or traveling long distances you may look at using two lighter bags and a couple of foam pads under you.

I recomend a balaclava rather than a toque for sleeping at night as a toque will work its way off your head as you sleep. I also put boiling water in a water bottle, wrap it in some clothes and stuff it in the bottom of the bag to keep my toes warm but make sure that the lid is on tight.

Can anyone please tell me how the Thermo-Lite Bivy and the LAND/Shark bag compare? Is one tougher than the other?

Great question, I've been looking at both, trying to decide which one to order. I hope somebody out there has experience with both and steps up to the plate.

Troy

I find that most sleeping bags exagerate their temp rating. I aim for a bag that is rated at least 15 degrees warmer than the coldest conditions I expect to face.
A liner is a good idea that adds flexibility, but 15 degrees is the most it can add. Wearing insulated clothing when you sleep can help, especially insulated booties for your feet(which are great to have around camp, and almost a necessity for winter camping).

I've only direct experience with the Thermo lite, which is tougher than anything mylar, but not indestructible.

I really want to get a Land Shark and give it a going over. Sight unseen, my guess is it is about as tough a survival bag as your ever gonna come across in this day and age. I may just order one after Christmas. I'm thinking it must be of the same constituency as those HD survival blankets they sell for $12 to $15. If so, they will be bulkier than the Thermo lite, but pretty darned rugged.

I was mainly wondering if there is a difference of insulating qualities and toughness of the two. I have two LAND/Sharks in my BOB. They seem to be aimed mainly at water-based emergencies, the package stating "In water with life vest on, open Survival Bag allow Bag to fill with water and climb in." It also says they will burn if ignited (though I suppose all plastics will burn 'if ignited'). They have a drawstring closure and a clip to hook to others in the group to keep them from floating away from each other. They come sealed in a 'metalized' plastic package that must be torn open to use while the Thermo-Lite comes in a drawstring bag. That, to my mind, would make the Thermo-Lite more 'reusable'. Also, the Thermo-Lite comes in both a single and a double size. I've been thinking of putting a double-sized one in my BOB so if I'm with someone they can share it and if I'm by myself I can fold it in half and double the amount of insulation underneath me. Although I can't see myself floating around a large body of water any time soon, I can see myself spending an unexpected night out in the sticks (I live in east PA). I bought these thinking I could build a debris hut around them and ride out a storm in a little more comfort. (The sealed package of the LAND/Shark measures about 8x6.5x1.5".)

Carry the ThermoLite bivvy since buying couple of months ago, but haven't tested/used under actual conditions – just post-purchase inspection. Chose it for: weight; price; stuff sack; non-conductivity; "ventability."

Key facts on the three products I focused on: AMK TL Bivvy, the Land/Shark, and the Blizzard Survival Bag (similar to other two, but has its own unique features).

• Cost - Bivvy $22.95; Land/Shark $39.99; Blizzard $44.30
• Size - Bivvy & Land/Shark 36"x84"; Blizzard 88"x107"
• Packed Size - Bivvy 4 x6" (cylindrical); Land/Shark 8"x6"x1"; Blizzard 8.3"x4.3"x1.2"
• Packed Volume - Bivvy 75.4 cu.in.; Land/Shark 48 cu.in.; Blizzard 43 cu.in.
• Weight - Bivvy 6.5 oz; Land/Shark 18 oz; Blizzard 12 oz
• Conductive? - Bivvy no; Land/Shark yes; Blizzard yes (factor if you expect to encounter lightning)
• Stuff Sack - Bivvy included; Land/Shark $6.95; Blizzard $8.85
• Material - Bivvy ThermoLite 4-ply polyolefin; Land/Shark aluminized film laminated w/compositie reinforced ripstop material (like Benjammin said, material sounds similar to Space All-Weather Blanket ; Blizzard Reflexcell 3-layers of insulating air cells w/aluminum coating.
• Misc - Bivvy is softest & can be vented; Land/Shark appears to be most durable; Blizzard looks to have pretty good thermal efficiency and has body-hugging elasticized construction.

The hardest thing to quantify was the relative efficiency (under same conditions, which keeps you warmest?) of each; the manufacturers tend to not present their info apples-to-apples. I will say, the Blizzard offers some interesting performance comparisons. Is it just well-presented marketing hype? I don't know.

Thanks for the rundown, from the posts so far, I'm leaning toward the bivy myself, while stowing it between uses isn't an issue with me, and I,ve pretty much got the camo issue covered (netting, poncho, & liner), I'm getting the impression that the bivy is designed for repeated use, while the "LandShark" is more of a "use it in an emergency, then replace it" item. Anybody out there seen them side by side???

Troy

Great comparison(s), thanks!
Looks like the choice is still between the bivy and the "LandShark", and I'm still leaning toward the bivy, but just curious, if you were buying over, would you go with the bivy again, or try the "LandShark"?

Troy

I'd go with the bivvy again (and some of my reasons are admittedly subjective/personal preference).

I like its softness and flexibility. My sense is that the Land/Shark is less flexible, if I'm correct in assuming it shares physical characteristics with Space All-Weather Blankets, a couple of which I have; and the Blizzard Bag strikes me as being a little less durable. Let me hasten to add, I couldn't find the Shark or the Blizzard at local retailers to inspect first hand. Since I could the bivvy, the benefit of hands-on inspection tilted the scales a tad.

Also, having spent an eternity wrapped in a single-ply space blanket w/sleeping bag one night years ago (the sleeping bag I brought was a miscalculation on my part), the ability to vent the bivvy was appealing.

And while it's somewhat more bulky as purchased (loosely rolled in the stuff sack) than the other two, the cylindrical shape packs nicely in my fannypack and daypack (doesn't hurt that it's featherlight too).

On that note, I should have mentioned that I re-rolled the bivvy so it's tighter, then secured with two ranger bands before putting back in stuff sack. Now, its volume is pretty comparable to the other two.

I liked the non-conductivity. Certain times of year, Arizona can get unpredicatable thunderstorms, and the lightning can be a sight to behold. If I can carry something that won't increase my odds of getting zapped, that's good.

In the end, it was, "Each of them requires some compromises; which are less important to me?"

So short answer, yep, I'd buy it again. In fact, I could buy two for the price of one of the others. <img src="/images/graemlins/smile.gif" alt="" />

"buy two for the price of one of the others"
Yeah, I have to say, that's a pretty big selling point, and I haven't seen any thing to suggest that the 'Shark is THAT much more well made...and, considering that I'm not planning on using it "stand-alone", but as a liner/cover, I think I'll go with the bivy.

Thanks again,

Troy

I just read a story of a guy using the Bivy Bag by pulling it on over his head, up-side-down, and using the foot vent to breath through...
That might work!

Great ... Cold weather survival meets haloween <img src="/images/graemlins/smile.gif" alt="" />