Summer without a sleeping bag or tent?

[Supertramp]

No it doesn't reflect body heat, but it's not the most breathable stuff around either, so some heat would be trapped inside.
My comment was mainly in reply to all the people banging on about vapor barrier's & what not.

If summer where the OP lives is anything like in Canberra, you don't need extra warmth at night

[icefest]

What about using some of the new breathable cuben fiber instead of a space blanket?

Might be a much better option instead?

You'd be better off with the lightest nonbreathable CF, but that doesn't reflect heat. (There was a silvered version of CF, but that had a nasty habit of delaminating).

It'd only be worthwhile if you use insulation inside it, as a UL eVent bivy replacement. (I'm fairly sure pure DWR is still lighter)

EDIT: Also, third gen breathable CFis well within one order of magnitude of breathablity of goretex and eVent.

[Orion]

The problem with the type of material that these space blankets are made out of is that they tear easily, and any small hole easily become much larger as the rip can grow without much resistance. If the reflective material had a plastic backing, similar to that of a garbage bag that can deform slightly before a hole forms, any small tears that form in the reflective material will not cause any major issues as the plastic backing that has stretched to accommodate the hole, prevents the movement of air through the bag.

Not sure what product you were using exactly as there is more than one type of emergency space blanket on the market. The lightest I've seen are aluminized mylar and tear very easily. I've slept "comfortably" in these on a number of occasions -- by comfort I mean thermal, not overall since I was sleeping on ropes/dirt each time. I should add that I have never planned such a bivy but rather took this gear because there was a significant chance I wouldn't make it back to camp and carrying real bivy gear was out of the question.

To augment these mylar emergency bags I sometimes take a large "contractor" garbage bag, typically 160 liters x 75 microns. In conjunction with the metallized mylar this has kept me warm enough on relatively benign summer nights at 3000-4000 meters. These large bags also function well as a pack liner.

Another type of emergency blanket or bag is made from aluminized polyethelene. They are slightly heavier and bulkier but appear more tear resistant. I haven't had the misfortune of an unplanned bivy while carrying one of these so I cannot report just how tear resistant they are.

While it seems like stupid light to plan on a night in one of these I could imagine situations where it might make sense.

[Allchin09]

Orion - It sounds like that type that I was using was the aluminised mylar type that you described. I will have to see if I can find the polyethylene type which sound like they may be more suitable for what I was looking for. Is this similar to what you were talking about? http://www.ebay.com/itm/Coghlans-Therma ... 2a31d2844a

[Nuts]

ACR make a breathable 'emergency' bivy? Relatively cheap and light.

Damn acronyminins, bum steer. Tis' AMK

http://www.adventuremedicalkits.com/pro ... oduct=263#

Really, emergency blankets are for a couple of hours waiting for the bananas bus. Coloured mylar, i'd say window film would be stronger. Personally I doubt silver makes any real difference.

I'd probably try the AMK, 'Space' brand make all-weather blankets. Ripstop coloured aluminised mylar, strong enough but they're getting heavier.
My choice as a single shelter if at all expected to be used would be a proper waterproof bivy, event, gore.. no proprietry fabric.. otherwise they invariably aren't waterproof and/or don't 'breath' well enough (expect around 500g's min, maybe a bit less with a cuben floor)

[Allchin09]

That escape bivvy looks like it could do the trick!

[Moondog55]

Let's look at this another way.
If it's warm enough not to need a sleeping bag or tent then the bugs and mozzies are going to be very active and after being eaten alive more times than I care to remember when I was younger I think; at a minimum, a mesh tent is absolutely needed for sanity and any sort of sleeping comfort.
A mesh tent combined with a "Space Blanket" the HD type could also be a lifesaver when the temperature got above 40+ too although a small silnylon or Cuben tarp would also do that job

[Nuts]

Haha, yes, we tend to forget about hot weather. I couldn't think of anything worse than bugs or a sweaty enclosed bivy bag as choices.
(which even includes here in Tas in mid summer) (ps. even with a mesh bivy window)

[Strider]

That escape bivvy looks like it could do the trick!

Except its only around half the weight of a lightweight real sleeping bag.

[Franco]

I have a strong dislike for these kind of "solutions" because from the "maybe we can do this" backyard experiment they can turn into a reality for the inexperienced.

To give a specific example, a mate of mine a couple of years ago during a bit of a white-out (in the middle of winter) on Mt Sterling came across, early one morning, an elderly woman inside a plastic bag curled up under a tree about 200m or so from the Geelong Grammar School hut.
Of course she had no idea whatsoever that the hut was there nor really of where she was at all.
Another few hours max and she would have died of exposure.
She was completely wet and of course shivering.
Took my mate over an hour to get her into dry clothes, (he was leading a group of students) giving her progressively warm drinks waiting for the rescue snow sled to come and pick her up.
Turns out that she had read about using a plastic bag as a substitute bivy in a forum...

BTW, I do realise tha summer temps are different and that at 18 you like to suffer just to prove a point, still why should you ?

[Orion]

Orion - It sounds like that type that I was using was the aluminised mylar type that you described. I will have to see if I can find the polyethylene type which sound like they may be more suitable for what I was looking for. Is this similar to what you were talking about? http://www.ebay.com/itm/Coghlans-Therma ... 2a31d2844a

No, that one is pretty big and bulky. The kind I meant is smaller, more like the mylar one: http://www.adventuremedicalkits.com/product.php?product=147

When I've had to bivy in a fist-sized emergency blanket the problem was not bugs, it was wind and cold. Nothing severe (no colder than 5°C), but without a sheet of material to create a bubble of air I wouldn't have slept at all in those conditions. And of course I also wore all my clothing which included raingear. I have only bivied like this when I didn't make back to camp from a technical climb. We knew in each case we might be benighted but carrying full bivy gear was impractical, especially with regard to additional water.

What is the bushwalking scenario you are considering where carrying an ultra-light sleeping bag, pad and tarp is too much?

[wayno]

when i was a teenager, i knew a lot of other teens who bushwalked, every single one of us had a nightmare tale or several to tell of doing stupid things in the bush, of being ill prepared, of lucky escapes. because we were full of energy and enthusiasm and short on experience and didnt know any better.... I had hypothermia a couple of time and came close to it several times more.
theres bad weather and bad gear and THE TWO SHOULD NEVER EVER GO TOGETHER.

[forest]

theres bad weather and bad gear and THE TWO SHOULD NEVER EVER GO TOGETHER.

Great call !!

[Orion]

"There's no such thing as bad weather, only inappropriate clothing."

I've seen that quote attributed to Ranulph Fiennes.
But in any case I think the corollary is that there is no bad gear only gear that is inappropriate for the conditions.

[ryantmalone]

Hey all,

What are your thoughts on bushwalking in the summer without a sleeping bag or tent, but instead using one of those emergency space blanket survival bags as a tent + warmth replacement? I would still use a foam roll mat to protect the bag and to provide some insulation from the ground.

I'm sure it wouldn't be the most comfortable or quiet setup, but it sure would be light and pocket sized!

A sleeping bag has saved my life more than a few times in Summer. To hike without one, in my honest opinion, is just pure stupidity.

[Allchin09]

Ryantmalone - You seem a bit dissmissive of the whole idea. Surely there are other alternatives to the traditional sleeping bag and tent setup. I am now looking at a bivvy bag with warm clothes setup. What is the difference between that an a lightweight sleeping bag? At least the clothes have more than one purpose!

[wayno]

you have to pick your clothes carefully to get the same warmth as a sleeping bag,
most down clothes are stitch through construction with cold spots. down bags usually have baffled compartment, eliminating cold spots. generally sleeping bags give you better warmth for weight, that few hundred grams of bag can make a big difference in warmth... so you might be hot in a sleeping bag in summer , but ditching it isnt as simple as it seems.... if you think you'll just throw on a couple of items of clothes and a bivy bag to make up for it you may find you still don't get comparable warmth....

[Mark F]

There is no significant difference between a set of down jacket and pants compared to a sleeping bag. With what is in my cupboard I would be using a Crux Halo jacket (290g) and a pair of WM Flash down pants (207g) compared to a WM Highlite bag at 480g - line ball. If I swapped in my MB Ex Lite Jacket (175g) I would be about 100g under the sleeping bag but I wouldn't be as warm.

[wayno]

Mark - whats the rating of the bag, and what temps have you slept in the down clothes?>

[GPSGuided]

The tent also acts as a big air insulator, where most people test their bags.

[Mark F]

I have always carried a sleeping bag, now a quilt, and only used down clothes to extend the temperature rating of the quilt. I was quite comfy camped outside Whites River in late April with the temperature at -7 (measured) using my MYOG quilt (about 0 rated) MB Exlite jacket and WM pants (in a Zpacks Hexamid without an inner). In these sorts of conditions the use of the down clothing before going to bed makes them more useful than a warmer bag. But this isn't what this thread is about. In warm conditions I expect that I would not have the flexibility to easily adjust my insulation if using clothing rather than a quilt. Its a bit hard to slip half a leg out of pair of pants if it gets a bit warm.

My personal preference for warmer conditions is a quilt compared to clothing or a sleeping bag (or even an inner sheet) because of the quilt's ability to easily adjust to the changing air temperature and the body's heat generation which decreases during the night. A quilt doesn't need to be down, it could be a light fleece blanket or even a silk sheet.

I feel there are different answers depending on whether we are talking about minimum temps above, 5, 10 or 15 degrees.

Wayno - the Highlite is rated as +2C.

[Moondog55]

Having bivvied in the snow more than a couple of times Mark I have to disagree with you, warmth for weight a sleeping bag will almost always be warmer than the same weight in clothes. It has to do with keeping the total air-mass still, even a very lightweight sleeping bag over the warm clothing works much better than wearing the same weight in extra clothing, it is the same reason mittens are warmer than gloves. It's why I still like half bags/ elephants feet.
I have to say tho that when I was younger [ much younger] we often took to the bush with just a lightweight woollen blanket and a groundsheet, we also often woke up stiff wet and cold but in summer you warm up quickly.
In America the lightweight poncho liner is popular as a summer alternative to a sleeping bag; in mild conditions and not in the mountains; so at a minimum an ultralight flat quilt may be the best alternative, especially if the outer fabric was a very "breathable" water resistant fabric.

[wayno]

to clarify, my earlier comment was to do with sleeping in clothes alone, and not sleeping in clothes with a lighter bag or quilt

[Franco]

There are many types of Cuben Fiber fabrics.
Brooks Range made a tent with a heat reflecting layer but in use that layer delaminated.

[Joomy]

That escape bivvy looks like it could do the trick!

Except its only around half the weight of a lightweight real sleeping bag.

Yeah but you still need some kind of shelter presumably unless we are indeed talking about situations with no chance of rain.

I really wonder if a ~50g Emergency blanket/bag is really ever that much more convenient than say a Malachowski bivy at ~227g unless one was planning to carry it in a pocket rather than in a pack. But if you had a pack at all then a bivy bag the size of a water bottle would surely never be too bulky or too heavy to carry.

[Gusto]

Why sleep at all. Just keep walking through the night. That would be lighter and more comfortable.
or..
sleep during the day in the shade and walk at night.

[Supertramp]

Why sleep at all. Just keep walking through the night. That would be lighter and more comfortable.
or..
sleep during the day in the shade and walk at night.

Then you'd need to carry a lot of batteries

[andrewa]

Mark F, I agree with your concept from a practical point of view, however, the reason a down suit never replaced a down sleeping bag was that there was more surface area to the suit, and therefore more heat loss for the weight. On the other side of the coin, the loathing option offers more flexibility. This is why I use a combination of insulated clothing and lighter quit for my camping/ski touring. I also have a Montbell ex light jkt. For me it wouldn't be warm enough to sleep under about 15c, but it does nicely augment my 400g to make it comfy to about 8-10c

The other issue to consider is wind chill. A tent offsets this. We recently had a night on Bogong that was so windy that the wind coming under my Hilleberg Nallo ( given that the the fly comes down to ground level) was enough to cool me down significantly inside.

The bottom line is that there are some situations where no sleeping bag or tent might work. I'd check the weather report carefully beforehand, and chose the situation. But I'd rather have a light quilt and tarp as minimal gear.

A

[wayno]

down suit works out heavier for the warmth, more nylon fabric, arms and legs loose more warmth in a suit than in a bag...
but down suit more practical moving around the campsite...

[Mark F]

As alluded to in my previous post, for me the use of clothing to sleep in is only as an adjunct to the use of a quilt (or sleeping bag) to extend the temperature range of the system. In warm conditions I normally adjust my level of insulation several times during the night as the temperature and my metabolic output change. Clothing is relatively inflexible in this regard whereas with a quilt it is really easy to slip a leg or arm out or move the quilt to cover more or less of my torso with minimal disruption to my sleep. The beauty of using clothing to extend your sleeping system is that it is dual purpose. Even though it weighs a bit more than a warmer sleeping bag, it functions as camp clothing meaning that you end up carrying no more weight and possibly less. Using down clothing under a quilt will help minimise the additional heat loss you refer to Wayno.

Wind chill is the reason I choose to use an enclosed tarp (Hexamid+ with beak) rather than a flat tarp. I have never been happy cowboy camping although I have done it many times.