Questions about cold

It could work and is all I use into the upper 20's. What sleeping pad are you using?

A few questions:

What sleeping bag are you using?
What's the coldest temperature you've taken it to?
How well do you tolerate the cold? Do you tend to run warmer than your friends?
If it doesn't work out, are you masochistic enough that a night spent freezing in your sleeping bag won't be a big deal or will it ruin your trip?

Edit to add: the 5* difference they're suggesting is a bit silly and a conservatively rated 30* sleeping bag may keep you warmer than a ambitiously rated 20* bag.

Another question:

What is the lowest expected temperature for this trip?

I was on a trip in Colorado's Lost Creek Wilderness last week and night time lows were supposed to be 50F, first night it was 28F and I was glad to have a 20f bag with me.

I know from experience I need a bag/quilt that's 10f lower than the actual temperature.

I don't think you are crazy. Mostly because this is what I do sleeping on a NeoAir Xlite. Make sure your pad is sufficiently warm and then layer clothing in as necessary, careful not to compress the down.

I honestly thought most lightweight backpackers did this.

If in doubt, heat up some water and put it in a Nalgene (one of the opaque versions at 3.2 oz) and then into your sleeping bag.

I am an avid believer of VB. I picked up a stephenson sleep system less than one year old for i/2 of list price on ebay including the 3.5 " thick r 15 insulated airmat. I believe someone in Alaska voiced for 45 below zero comfortable night.. I have about 100 bags many of the minus 40F variety and the Stephen wins hands down.
Regards
Paul

Thanks for this info. the bag is a Marmot Never Winter 30. I have never used it. I have a termarest and/or neolite. I guess I am normal in terms of cold tolerance. One night freezing would not ruin my trip, 5 nights might. The expected temps are 30 – 40 at night with a likelihood of rain. K

With predicted temperatures around 40°F you should be fine. But you will be at elevation in Colorado, and surprises are common.

Apologies if you already know this …

The specs on this bag don't mention a baffle opposite the zipper so you may be able to shift a large amount of down to the top of the bag. This will significantly improve performance.

Grab the open bag by the bottom zipper edge, hold it chest high, and shake it for a minute. You should see the top is now "over-filled" and the bottom "under-filled". (Don't get to carried away.)

Learn how to "sweep" the down back to the top while in the bag.

Have fun.

Most women sleep 10-15* colder then men. Your bag is is EN rated to 37.6*f for females so I would keep that in mind. Of course that is for the "average woman" so your experience may very.

If I were you I would want a 15 or 20* bag at 12k feet any time of year.

> I have a down bag rated to 30.
Ah, but who rated it?
If it has an EN rating, that is believable. But if it is just a claim by the manufacturer, it may not mean anything. Some USA bags have been *measured* as being up to 15 C wrong in their claims. (Guess which direction!)

Second, what mat? A poor mat will make you cold regardless. The amount of down under you does not really do you any good at all.

Third: what shelter? Under a breezy tarp, or in a double-skin tent? Air flow past your bag matters.

Cheers

Marmot is EN rated.

See Bradoford's post above.

Since your name is Kathryn, I'm assuming you are a woman. Keep in mind that most women sleep much colder than men. Like 10 degrees of difference when selecting a bag.

Have you used this bag before? If so, at what temps?

There are really too many variables for any of us to give you an accurate answer based off of the information we have to go on and your limited experience with your bag and pad.

Heavier thermals and wearing a down jacket to bed will certainly help, as will loose fitting socks and a beanie. How much extra warmth it actually provides is dependent upon how you fit in your sleeping bag, your metabolism, your sensitivity to feeling cold, etc.

Another thing you can do is eat before you go to bed.

If you can answer the questions from posts above I think you'll find some decent responses.

I would error on the side of being more prepared than less at that altitude. Weather can move in unexpectedly and it's not uncommon for forecasts to be off by 10F which when you're already on the edge can make for a very unpleasant time.

I can tell you that for MY wife- who sleeps kinda cold- we would have her FF 20* bag and it would be on a ProLite with something else underneath it like a GG Thinlite. The R-value of the NeoAir I think is 3.2 which might not be enough IF it gets down into the 20's, which you should be prepared for. Anything worse and your clothing will carry you through.

Based on what the Op has written here, I think a warmer sleeping bag and other down garments would be a better idea than this sleeping bag.

… for someone else. I find that the range in what different folks find comfortable is huge. I use my Mountain Hardwear Phantom 45 well down into the teens F and sleep comfortably. At the same time others around me have said they were cold with a 10 F bag.

Then there is the fact that bag ratings vary over a similarly wide range unless they have EN ratings.

So you really need to figure out what works for you. Being a little cautious at first is a good idea if you are not willing to suffer a little. By all means don't go to the point of actual danger.

I have always ended up grateful for my 15 degree bag above 7000ft but I think if you wear everything including the puffy jacket and eat a bar before bed time, you should be fine.

Maybe not blissfully comfortable all night but certainly not in danger.

You can try checking a mountain weather site in your region to get a rough idea how low temps will likely dip on your trip.