Space Blanket for emergency shelter

Take the bivy. If you really need it as rain gear, cut a hole at the bottom and sides, like a poncho. EDIT: Multi-use bivy becomes vapor barrier liner for sleeping bag in colder weather.

Im I correct in assuming the bivy would be significantly warmer if I were to ever end up sleeping in it?

(vs. trying to wrap the blanket around myself)

If you're hiking solo, I agree with the bivy. I always hike with groups, so I like the blanket for the tarp option and that I can use the blanket for multiple people huddled together. I once used an aluminized emergency blanket overnight as a tarp backdrop to reflect the heat of a fire. It survived the night (thought it was starting to delaminate), and I survived in just my day-hike clothes.

Ken

Well, the bivy can be snugged up around you and is water tight, the basic heat sheet is not. I think the water resistance and lack of drafts in the bivy alone would give it an advantage. Keep in mind that with the Heatsheets products, the thicker plastic provides more warmth than the actual shiny backing. I know that some survival gurus love the heavy duty 3 mil orange plastic bags used for some road side trash cleanups.

If you have purchased the bivvy bag, you can use it as a bivvy bag, or you can slit it and open it up into an open sheet. If you have purchased the sheet version, you can't very well seal it up into a bag.

Years ago, when I was in military training in a hot location, we would spread out our ordinary ponchos on the ground, lay down on one side of it, and then roll up in a tube, and we spent the night that way. I don't think that would work for a cold location.

–B.G.–

>> If you have purchased the bivvy bag, you can use it as a bivvy bag, or you can slit it and open it up into an open sheet. If you have purchased the sheet version, you can't very well seal it up into a bag.

Very true, Bob. Never thought of it that way.

Ken

for all the reasons listed above …

and you can use it as a vbl if needed

Im sold on the bivy. If I ever need to use it, it sounds like I will be of more use than a space blanket.

As I run over survival situations in my head the bivy certainly has many advantages.

– as mentioned eariler, the bivy would probably make better rain gear if I was getting really cold

– could also stuff the bivy with grass/leaves to make a decently warm sleeping bag.

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Survival question/scenario

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It raining hard, I have to spend the night on the trail for whatever reason. All I have is my bivy and wet clothes (light wool t-shirt, shorts) I cant start a fire and have to get in the bivy soaking wet to spend the night.

I leave my cloths on because wool will insulate even when wet, even though I would probably stay wet the entire night. In this situation would adding wet grass inside the bivy be a good or bad idea to add extra insulation?

The obvious answer was "bad idea", but then I got to think how wetsuits work. Would my trapped body heat inside the bivy be enough to warm up my wet cloths and grass insulation? Or should I just try and stay as dry as possible inside the bivy with just my lightweight clothing?

In military training parlance, you want to build a squirrel's nest. That is a pile of leaves or other vegetation with or without any bivvy bag to help. If the vegetation is damp, then the bag helps to keep the vegetation on the outside and keep dry next to your body. If the vegetation is dry, then it works better on the inside.

I am reminded of a survival case some years ago when an off-duty U.S. Marine was hiking a little north of Yosemite when he fell from the trail off a cliff and broke both legs. His fall was into a stream bed, so he had a trickle of water to drink. He built a squirrel's nest of leaves to sleep in and simply survived for two or three weeks until he was able to crawl back up to the trail and crawl out to the highway to safety.

–B.G.–

Please pardon the thread drift.

@ Bob,

"I am reminded of a survival case some years ago when an off-duty U.S. Marine was hiking a little north of Yosemite when he fell from the trail off a cliff and broke both legs. His fall was into a stream bed, so he had a trickle of water to drink. He built a squirrel's nest of leaves to sleep in and simply survived for two or three weeks until he was able to crawl back up to the trail and crawl out to the highway to safety".

HooRah!

Party On,

Newton

for day hikes I carry both, a 2 person heatsheet and the bivy- most likely shelter options are- they are both the size (and weight) of a deck of cards

A: lean to using the heatsheet, long fire and myself in the bivy

B: debris shelter where I stretch the heatsheet over the rudimentary frame and then heap debris over (and in) the shelter- again myself in the bivy

if forced to choose just one, I likewise say the bivy

having slept under a double sided survival blanket (I think it was a AMK blanket) one night, I can tell you they do not provide much warmth- the bivy will be better. The blanket conforms poorly to your body thereby allowing much of the heat to escape. I remember thinking: if the astronauts have to rely on this thing they are in real trouble. It was only one night & the temps were in the 40s even with an insulated jacket on i was cold below my knees.. A scout forgot his bag so i gave him mine & tried the blanket.

I carry the bivy. The blanket is good for waterproofing an improvised shelter or ground sheet and is easier to get around an injured person. The bivy will give all-round protection and can be cut open for the other functions.

As far as space blankets being warm: they are warm like a thin rain shell or windshirt is warm– it will cut the wind and keep you dry, but there is no insulating value. You will want a bed of duff or boughs to insulate from the ground and the more clothes the better. If you spend a night in one, it won't be warm and cozy, but you may live to complain about it :)

For what you are doing I'd simply bring the "Oh Sh!t" space blanket. You'll end up shivering no matter which one you have should you get stuck with an unplanned bivy so I'd go with the lightest simplest one you can get.

I basically decide what the odds are I'll be stuck overnight and for most planned "full day" trips I pack nothing more than a simple space blanket. Then in case something goes wrong and we have to "sleep" somewhere it at least provides a cover from rain/wind/cold to some extent. Though most of those nights I don't end up sleeping much or for very long, but I've logged at least a dozen "unplanned" bivies that way.

My next step up is to actually bring my MSR e-bivy and my 1lb WM sleeping bag. Those trips we usually figure that a bivy will happen and only if we are moving fast and are lucky will we be back to camp for night.

Why not an additional 4-5oz for a 5×8 tarp as an emergency shelter? Far more useful.

I try to work trail traffic into the equation. If I'm out early in the day (mountain biking) on a high traffic trail, I don't worry too much. For less traffic I take a 99c space blanket and 99c poncho. If I was out someplace where I might not see others for days, I'd take … my new tarptent!

(Maybe I'm conservative, but I wouldn't run/bike solo and gearless off the beaten track.)

Also these:

http://www.hardwareandtools.com/Husky-HKK55030B-55-Gallon-1-Mil-Cleanup-Bag-For-Leaves-and-Drum-Liner-Box-of-30–073257003391.html

I just googled and found that site above, but I picked up some from a hardware store when I needed some really tall bags for a project. Only 1 Mil thick, but over 4 ft in length. You wouldn't really notice a couple of these in the bottom of your pack and you could pull one over your lower body and another over the top with holes cut for head + arms.

I was on some Scottish website and saw a description of some pod-like things, that were more spherical bivvies. The cool thing was that 2-3 people could huddle in one for warmth. For that they didn't seem much heavier than an emergency bivvy. I thought they were neat.