I have a 40 degree mummy bag but in a couple weeks im going back packing in yosemite where the expected low is from 15-20. i dont have the money to upgrade my bag. i was thinking i would sew a cotton bed sheet to the shape of the bag to give me an extra layer. any other ideas would be very helpful, cause im a wimp in the cold ;)

thanks

Wear all of your insulative clothing...including things like your rain gear.

Absolutely. And use a bivy sack. Also, wear an extra vest and warmer insulation in your feet and head- especially a balaclava.

Last, and maybe most importantly, increase your pad insulation. Put an extra foam pad underneath- a lot of your warmth is lost to the ground.

Best of luck!

Getting a 40 deg bag to 15-20 deg if you're "a wimp in the cold" is going to be tough. What clothing options do you have?

Honestly borrowing may be the best option. Do you have anyone you can borrow a 15deg bag from?

I'm no pro, but IMO that's a big push.
I agree that wearing all your clothes and beefing up your pad will get your bag to a lower temp - but probably the smartest thing to do (apart from borrowing someones 15 degree bag as per Mr. Plesko) is to make sure you have an easy out during the trip...ie. the car is close to your proposed campsite.

You MIGHT manage with a good sleeping pad (Exped downmat 9 for instance) and insulated clothing with hood or hat.
What I have done in the past and might work for you is: backyard or car camp in the temps expected (with ALL available gear with you-beg,borrrowed or stolen) and then try out a couple of nights switching out gear as needed until you hit your "sweet spot" at those temps.
Two nights of intermittent sleep sure beats a week of lousy sleep. IMHO

We had a kid use a single 40 bag in 17F weather last year, the next morning all of his toes were blue and feet stiff as a board when he didn't follow directions for putting 1 40F bag inside of the other 40F bag, "too hard to do" he said.

While you've been offered a lot of sage advice (although I'm surprised no one suggested a very warm girl friend), you really do need a bag or system tested to the 20F range.

Otherwise, what's your backup plan if it turns out too cold, or it gets down to 10F at 2 in the morning, what are you going to do?

REI (and others) rent bags, that might be an alternative, but as one noted, you really need to know your solution isn't going to end up with feet you can't hike out on.

Good luck,
MikeB

It would requre approxiamtely 1.94 clo of clothing to be worn in your 40 degree bag to bring to acheive thermal comfort equivalent to a 20 degrees F bag. To achieve this would require ~1/2" of clothing covering your body without compressing the bags loft (don't forget head, hands, and feet).

I suggest you follow the sage advice given by the preceeding posters.

Edited by richard295 on 10/31/2007 23:14:30 MDT.

> i was thinking i would sew a cotton bed sheet to the shape of the bag to give me an extra layer.
If it was this easy to upgrade a sleeping bag from 40 F to 20 F, why would we bother buying more expensive bags with LOTs more down???
No, it WILL NOT WORK.

Whatever you do, remember: a GOOD pad under you, and GOOD balaclava on your head.

Cheers

I've gone car camping many times with with a synthetic bag (rectuangular style - no hood) from Costco rated to 32 degrees. I would imagine 32 is a very generous rating for it. I've pushed it many times into the teens and once to 9 degrees. During that 9 degree night, I wore a layer of polypropylene and two layers of thermals. I had my coat layed over my chest and a wool blanket around my lower half. I had two pairs of socks on (making sure to give space between my toes and the socks - if they are right up tight against them they won't stay warm). I wore a beanie that covered my entire neck and sides of face. Eat well and run around camp before getting into bed. I was fine.

Unfortunately, that was car camping, and I was able to bring all that insulation. Unless you have high-loft clothing, I doubt you could fit in your pack the necessary blankets, thermals, etc needed to keep you warm. That kind of insulation doesn't pack small and it weighs alot.

Good luck - and let us know what you end up doing.

If you are backpacking for more than one night out...I'd probably not try that. Be ready for potentially being uncomfortable on your entire trip if you chose this route.

Sharing a tent can significantly change the inside tent temps. That might be the best move if you are dead set on trying this, along with everything else people are mentioning.

Try:
1. Share a tent
2. Wear more insulation to sleep, including for head/feet
3. Use a bivy
4. Put hot water in leakproof container inside your sleeping bag
5. Beef up the sleeping pad
6. Use hand/foot warmers
7. Avoid alcohol

Edited by jshann on 11/01/2007 07:51:03 MDT.

Down booties will help....Nice for the midnite run also...

Pan

ive taken my 40* quilt to about 15* before, but it took a lot of supplementation. Capilene base, 100 wt fleece, thermawrap parka on top. Wool pants, 200 wt fleece pants, and a down jacket wrapped around my legs. I used a reflective VB liner around my clothes, then the quilt, then wrapped up in my tarp in an AT shelter. I was still a little chilly and I normally sleep really warm. I can't recommend you try similar things at all. It would take more than double the insulation your 40* bag provides to get you to 15* in the same comfort.
All I can say is get a decent bag rated to 10* somehow (borrow, rental, etc) and don't worry about trying to get a 40* to magically drop its rating.

> Try:
> 1. Share a tent
Share a quilt!

> 2. Wear more insulation to sleep, including for head/feet
Especially your head.

> 5. Beef up the sleeping pad
Yes

And eat a really good dinner.

Cheers

If possible, take an extra person along to share your tent. When my wife still hiked or when my children were smaller and we shared a tent, I could count on taking a lighter weight sleeping bag or even sleep with the bag partially unzipped because these little guys threw off so much heat. A couple of years ago hiking out of North Lake with one of my sons, we experienced ice in our water bottles just about every night but I had difficulty sleeping because it was too warm sharing a two man tent with him.

You can use plastic bags over your base layer and under your sleeping socks and gloves. Safeway veggie bags. It may only add a little warmth but they are cheap and light, and who knows it might get colder than the "expected lows".
They do make Vapor Barrier clothing and bag liners. Maybe 5* pickup depending.

Don't breathe into your bag. Balaclavas help with that, and don't fall off your head while you sleep.

Borrow a fat pad or 2, it may be heavy but its worth it to have: one thermarest and one foam pad. Foam pad on bottom.

Sleep on dry ground. South faces may get quite warm during the day so look to camp there.

Sleep under a thick tree to exchange some radiant heat with it, rather than the great void. Shelter from the wind is also something to look for.

Lots of food. Hot water bottle. Try to sleep in between your buddies!

Recently I had the opportunity to compare the comfort level of a group of people using similar equipment . The greatest differences became apparent after a few nights with a low of around or just under 0 C (32F).
My conclusions are that you will be more comfortable if :
1) you wash all of the dirt and sweat off your body (as soon as you arrive at camp when you are still warm) and change into dry clean clothes
(tip, take some plastic bags with you to wear on top of your dry socks at camp, so that your boots don't get them wet/dirty They look funny but nobody laughed at me after the first few nights)
(put your dirty/wet clothes on again when you start walking the next day)
2) have a hot dinner and a walk around camp just before you go to bed. Make sure you have some fats in your diet (olive oil is an easy fix)Take a hot drink with you and drink it once you are inside your bag. (hot chocolate with full cream milk will help.Definitely not coffee or alcohol. Chai was my choice)
3) supplement your mat with the infamous (but cheap) blue mat ( a second one if you already use one) You can also put your raingear and day clothes under the mats. That helps me to "level the ground" .
4) wear socks,gloves and a warm hat (fleece or wool)
5) get a liner. I like silk. (not cotton....) and don't bother with the fleece versions
6) optional and not politically correct. Get a pee bottle. My hot pink wide mouth bottle caused some hilarity, but again not after the first few nights.(my other bottles are Gatorade, I can tell them apart in the dark...)
If all of the above does not help, you will not die but you will find a way to save up for a warmer bag.
Franco

David- you had it all hanging out on that one! Sweet! (or dumb, depending on your perspective :-)

One time I was in the Enchantments in Washington- late fall. 5 feet of snow and every lake was frozen solid. I found one bare patch of rock to pitch my Gossamer Gear Spinnshelter. BMW Torsolite with an underrated Montbell Bag and a BMW bivy. Not much as far as warm clothes and that rock was SO COLD. Winds blew out a seam on the shelter. Not a good night- I had my legs supported by my shoes for extra insulation.

However, it was one of the most amazing days I've ever had the next day! Check out these pics!

I'd never push a bag like that again- it was ridiculous! So move forward with caution when pushing it. The risk I took on this trip was stupid and things could have gone badly. Luckily they didn't...

Edited by djohnson on 11/05/2007 23:57:24 MST.

thanks, i like to think it was on the sweet side as opposed to dumb, but thats certainly up to interpretation. i'm pretty sure i was letting someone borrow my 20* quilt on that one and just had to improvise to keep good company on the trip.

I've never had a seam blow on a shelter before, but I also haven't camped on an area that exposed! that looks like it would have been a terribly windy nights sleep even before the failure. With everything soft and white around you i guess you were stuck between a rock and a hard place...

sorry i had to go there

the day after cold nights like that where it nears the misadventure or "epic" stages are the best though. the afterglow i had from that night and one similar one lasted for weeks after the trip was over. you can see that victorious/relieved/ecstatic look on your face in the last pic too. good times :)

I totally agree David- those long nights can sure end in beautiful mornings.

And I sure wasn't calling you dumb (at least not without calling myself that too!) But while I might have accepted a certain amount of risk in the past, I definitely wouldn't suggest it of others. :-)

Keep having great adventures!

Doug