- 35 sleeping bag advice

[Green Knight]

Hi Folks,

Need some advice regarding sleeping bag setup in 0 to -35 temps.

Currently have Silk liner, woodlore osprey and goretex bivi bag setup, which has only been tested in - 5 conditions.

I'll be going to Norway on the Arctic expedition in February and could expect -35 temps.

So my thoughts, instead of buying a -35 comfort sleeping bag, much £££, i'll buy a down bag to add to insulation with my current setup.

Any thoughts or recommendations? would this work?

The woodlore Osprey is Synthetic, this as well as the bivi bag so would protect the down from getting wet.

 

[mountainm]

If you're putting the down bag inside the synthetic then wont it compress the down? I wondered if you could hire a bag anywhere?

 

[sandbender]

I used a Woodlore Golden Eagle bag on their Arctic course, it isn't rated to those temps but I managed fine, temps were -35 to -40. Obviously I used a bivi bag and decent mat too.

 

[Andy BB]

What are you sleeping on? A good insulating mat could make all the difference.

 

[Scots_Charles_River]

In those temps sleep in your clothes or a sleepsuit like a fleece one piece 'onesy'. In cold temps I sleep in my one piece fleece suit that's an undersuit for my drysuit.

 

[mountainm]

In those temps sleep in your clothes or a sleepsuit like a fleece one piece 'onesy'. In cold temps I sleep in my one piece fleece suit that's an undrsuit fro my drysuit.

But it's warmer to sleep naked in a sleeping bag don'tcha know okenest:

Disclaimer: it actually isn't.

 

[Barn Owl]

It's your body heat when naked that heats the bag, if wearing your clothes that heat can't reach the bags insulation properly.

I know that the drysuit underfleece nearly sweltered jag009 the other week, so that def' works.

 

[rg598]

Ditch the bivi bag. In such low temperatures it is not much use, and will just trap more moisture. I don't care what material it is made out of, at -35C the condensation will be extreme. If you get a down bag, use it over the synthetic one so the loft doesn't collapse. Theoretically it is better to have the synthetic one outside because that is where the most moisture will get trapped, but it just compresses the down insulation inside too much.

That being said, two bags should work fine as an approach if you can get the right temperature rating. Bring a mat of at least R5 insulation value.

 

[Imagedude]

Ditch the bivi bag. .

I found my bivi bag to be very effective at keeping the rain, sleet and spindrift out of my sleeping bag whilst in Norway last year.

 

[Scots_Charles_River]

It's your body heat when naked that heats the bag, if wearing your clothes that heat can't reach the bags insulation properly.

I know that the drysuit underfleece nearly sweltered jag009 the other week, so that def' works.

If your body is warm - layers and a fleece suit - then you need less dependence on a sleeping bag or outer layer. Personally I would rather layer up than have a very expensive down bag. But, a nice cosy bag and hood synched up is more comfy to move about within the bag.

 

[Robbi]

oh yes it is !

 

[sandbender]

But it's warmer to sleep naked in a sleeping bag don'tcha know okenest:

Disclaimer: it actually isn't.

Brrrrr.

In a snow trench, in a Woodlore Golden Eagle bag, which was inside a bivi bag I wore Woolpower 200g and 600g thermals, a merino wool hat and a single pair of very thick wooly socks. I was quite comfortable at -38 ish. Wearing more clothes might lead to problems the next morning if they have become damp through the night, the socks I wore on my feet were not the ones I would wear the next morning.

A bivi bag might seem surplus to requirements but I found that even the temperatures were freezing at night, things became quite balmy when the sun peaked over the horizon and the bag did keep spindrift off the sleeping bag.

 

[Green Knight]

Thanks for your thoughts,

I'll be using a Therm-a-Rest NeoAir Sleeping Mat which has a R 2.5 value, most R 5 Mats are too bulky for my style, don't really want to buy another as i never use it as i prefer a under quilt for hammock.

My personal experience with wearing thermals in sleeping bag was that with thermals i was cold, without very warm. (balaclava, socks, hat only)
Tested this theory on 2 nights, same temps and both nights no wind chill, as i was sleeping in a hammock.

 

[Chris the Cat]

Make sure you get in your bag WARM!
Do star jumps if you have too, and a hot drink.
If you get in cold , you will stay cold!
Have a great time and take loads of piccys!
Best.
Chris.

 

[Gray]

But it's warmer to sleep naked in a sleeping bag don'tcha know okenest:

Disclaimer: it actually isn't.

minus 5 night before last, issue arctic bag, 2 fleeces, jogging bottoms and thermal base layers.......I froze and then remembered reading this. I thought I cant be any colder so I stripped off and got back in, never in my life have i been more cosy in a bag....it was pure bliss. Toasty warm and loads of room to move because i wasnt wearing any clothes. I even slept in untill 0930 yesterday morning. I was always taught to add layers, just keep adding them till you warm up............rubbish

 

[mountainm]

minus 5 night before last, issue arctic bag, 2 fleeces, jogging bottoms and thermal base layers.......I froze and then remembered reading this. I thought I cant be any colder so I stripped off and got back in, never in my life have i been more cosy in a bag....it was pure bliss. Toasty warm and loads of room to move because i wasnt wearing any clothes. I even slept in untill 0930 yesterday morning. I was always taught to add layers, just keep adding them till you warm up............rubbish

So you got out of a warm bag, into the cold air. Took off your clothes making you colder. Got back into the warm bag and it felt toasty?

The other night I was sat watching tv and I felt cold. SWMBO asked me to go into the loft to fetch something. The loft was Icy cold, when I climbed back down the ladder the heat from the central heating hit me, immediately I felt too hot. The room was the same temperature as it had been when I felt cold but a little bit of movement and being transferred to a cold place quickly soon showed me how warm it really was.

The reason for this long winded but true story? Because adding extra working layers of insulation will always keep you warmer if you are the producer of the heat. This is physics.

The loads of room to move bit could also be a reason. If you wear so many layers that you can't move you're probably affecting the loft of the bag.

 

[blacktimberwolf]

Scientifically, it may calculate that it's warmer to sleep in clothes than naked but many folk find it more comfortable & warmer to sleep in the buff. I am one of them. Science doesn't have all the answers, for example according to the laws of physics, a bumblebee cannot fly....... and yet, the marine vocano chimneys with water at around 100 ° C , biologically no life can exist ..........& yet, volcanic lakes which are chemically far too acid to support life ............& yet.......................scientifically it's warmer to sleep in a bag, clothed .......and yet there are those who find otherwise.
The important thing I think is to find what works for you, clothed or naked & forget the science or explanations behind it.

 

[mountainm]

for example according to the laws of physics, a bumblebee cannot fly....... and yet, the marine vocano chimneys with water at around 100 ° C , biologically no life can exist ..........& yet, volcanic lakes which are chemically far too acid to support life .............

Science doesn't say any of this. The aerodynamics behind the flight of a bumblebee is well understood as is the study of extreme organisms. It's popular myth that says this, not science.
http://www.how-come.net/2009/08/17/is-it-true-that-bumblebees-shouldnt-be-able-to-fly/

But the science of insulation... Of thermodynamics, of convection currents and radiation is very well tried and tested.

 

[blacktimberwolf]

Science doesn't say any of this. The aerodynamics behind the flight of a bumblebee is well understood as is the study of extreme organisms.

Yes, now. .............when faced with things that in theory couldn't exist before, scientific thoeries & beliefs have to shifted around & explanations found.That's how science evolves. There are things yet to be discovered that with today's scientific understanding, cannot exist.
I am warmer sleeping nude in a bag & yet that probably goes against the current laws on thermodynamics , there must be a scientific explanation to it somewhere. ( & I don't mean psychiatric )

 

[mountainm]

Yes, now. .............when faced with things that in theory couldn't exist before, scientific thoeries & beliefs have to shifted around & explanations found.That's how science evolves. There are things yet to be discovered that with today's scientific understanding, cannot exist.
I am warmer sleeping nude in a bag & yet that probably goes against the current laws on thermodynamics , there must be a scientific explanation to it somewhere. ( & I don't mean psychiatric )

You are, and will remain without doubt an enigma to science.