Ordinarily, going from 75F to 20F in late April is not cause to rejoice. However, having just put together an insulated quilt, I saw this as an excellent opportunity for some testing. What I have is really simple - 72" x 60" of 5 oz. Climashield XP inside lightweight 1.1. oz. ripstop nylon. The total weight is 24 oz. and total cost was $77, including having a local sewing shop put a seam around it. My two goals were to have a light but warm emergency blanket as part of a makeshift shelter and to have something comfortable while waiting for shooting light. While I will avoid doing so as much as possible, it stuffs down to a little more than half the volume of my 20F Northface bag.
For my first test, I wanted to combine use of the blanket with sitting on the cargo chair attached to my Kifaru Pointman. To make up for the short length of time (30 minutes) I wore only two items I'd have out hunting - my insulated boots with wool socks. Otherwise, I had on a shortsleeve cotton t-shirt and jeans. I got the quilt wrapped around me as best I could, with some tucked underneath and sat with the pack leaned against a brick wall on an elevated wood deck. Even without a hat, I was quite warm the entire time. My only complaint was sitting in the cargo chair was starting to make my legs tingle towards the end. The temperature stayed at 20F with a light breeze.
I next put on a pile pullover and the jacket I always carry, along with the hat I usually bring with me and my hunting gloves. This time I used the pack as a pillow and laid the quilt out on the deck, folding half over my body and snoozed for another half hour. The idea was to come closer to replicating a makeshift shelter situation. What was lacking was my hunting vest, the long underwear I usually wear, my wind and water-resistant overalls instead of cotton jeans, and a longsleeve polypro shirt instead of the cotton t-shirt. Also, I would use the poly tarp I carry for deboning as part of a shelter and my game bags. Still, I was quite comfortable for that amount of time - as limited as it was.
This will do well for what I intend
Climashield XP and the nylon are quite comfortable, even against bare skin. The insulation just seems to radiate warmth.
Care must be taken to tuck the quilt in as well as possible (it's not a sleeping bag!)
Combined with everything else I have to wear or drape over me it would go a long ways towards preventing hypothermia, frostbite and death
I doubt that several hours into it I would still be feeling that comfortable
Despite the extra 6 oz. it would add, I wish I had ordered enough material to make it an extra half-yard wider (90" x 60").
A couple notes if you are interested in trying this:
I used Climashield XP, which is the second-warmest insulation I could find and is much more dimensionally stable than the warmest, which is Primaloft. Note too that other variations of Climashield, such as HL and Combat provide less insulative value than XP.
I went with the 5 oz. version because the 2.5 oz. version would have been too light and the 3.7 oz. Combat has 75% of the weight but only 71% as much CLO value.
I would avoid silicone-impregnated nylon. While tempting for waterproofing, if you build a fire and it gets ignited it will continue to burn on its own.
Thru-Hiker: Gear and Resources for Long Distance Hikers is the source I used and the service was great. I spoke with the owner, Paul Nanian, who is a very knowledgeable and personable guy and, although the shopping cart doesn't allow it, he'd probably sell you fractions of yards if you called.
I'm 6'0" and tend to sleep warm so this amount of material and insulation might not work as well for someone else
I went with black for the nylon because the other colors were not ones I'd like to have in the field. Another option, especially if you want to shave off a couple ounces, is their Momentum fabric. It comes in more colors but is nearly twice the price.
Last edited by jonoMT; 04-24-2009 at 12:49 AM.
Reason: additional info
Test 3: At 4:30 a.m. with the thermometer showing 15F, I went back outside. This time, I had on all the clothing I would have with me. I was also feeling dehydrated and hadn't eaten for 9 1/2 hours. This time, it occurred to me to use the two game bags that I carry to help make the quilt into a sleeping bag. These are high-quality and closely woven with minimal stretch. I folded the quilt in thirds so that it had a lot of overlap, then pulled one game bag all the way over it as high as it would go (about 2/3rds of the way). I laid it out on half of my 8' x 6' poly tarp on top of snow-covered grass, got into the other game bag, then got inside the quilt, with the overlapping folds facing down. Finally, I folded half the tarp over everything and tucked it in under my feet. Again, I used the pack for a pillow. I should also mention that I attached the hood to my jacket. I usually use it to carry my field dressing tools and other kit.
After an hour, I still felt warm. In fact, I was in danger of overheating and had to remove my hat, hood and gloves. I consider this a very positive test. Of course, in an emergency situation, where you might be injured, exhausted and wet, and almost certainly dehydrated and short on food, performance would be worse. I would certainly do whatever I could to use the terrain and whatever materials I could find in the immediate area to gain as much shelter as possible. If conditions permitted it, I'd build a fire. But I think this is a realistic example of using items you would normally carry for hunting to construct an emergency shelter. I am always trying to keep the weight down and this is a good way to avoid leaving essential items behind just to pare the load.
Do you carry this stuff on your back or the back of a four legged helper? It would seem that the tarp you use for deboning is a lot of weight and space compared to a 0.6 mil plastic sheet.
The other thought that occurs to me is that a space blanket is extraordinary light weight and is water proof and good for this sort of thing.
While the tarp weighs a little more than plastic sheeting, it's more durable. At least, last season, the flattest place I could find to debone and roll the elk to was still a rock patch. One thing I'm considering is switching over to sil-nylon, which is lighter than either.
I used to carry a space blanket but disliked the noisiness and draftiness. To me they just don't seem as effective.
My overall load is, depending on how much water I need to carry, between 20 and 25 lbs. Given that I have carried 80 lb. loads in on 10-day backpacking trips, I really don't find that excessive. I've also found that with high-quality equipment like the Pointman, you can carry more weight longer. Adding a gun bearer made it even easier to handle.