Cold Weather High Altitude Sleeping Question

[Dhamma]

Question:

 

What do you usually wear when sleeping in a sleeping bag in cold temperatures at altitude?

 

Bivyd in a lightening/rain storm at 10,300ft, I wore capilene 3 longsleeve shirt and pants and a north face denali jacket and i completely soaked my 15 degree down bag in sweat-rendering it soggy and heat-sucking.

 

It was probably below freezing with the windchill outside

[DonnieK]

If you were hot, why were you wearing all those clothes?

 

And the zippers work both ways - to close the sleeping bag, and conversely, to open it. Open = cooler.

[Dhamma]

i was cold when i went to bed so i had all that stuff on, but then i got too hot when i was asleep apparently

[LostCamKenny]

The sleeping bag is designed to take your body heat and use that to warm the space inside - pretty common knowledge, I'm sure. By wearing too much to sleep you are doing two things (that I see): 1. Your body heat has much more to go through in order to get in between you and the bag, and 2. when your body heat does finally heat up the inside of the bag you will be wearing these extra layers that will make you even warmer and then the need to shed these layers will probably result. My advice: Let the bag do its job. Wear a base layer to sleep (i.e. long johns and a poly long-sleeved top, and a beanie) and see if that doesn't keep you warm enough. This is what I wear and I have never had a problem being too hot or too cold at altitude. Keep in mind, though, that people can react differently to the same conditions. The denali jacket was probably overkill. If you are a bit chilly when you first get all the way in your bag with just a base layer on, wait for a few minutes... your body heat hasn't warmed the space up yet. Once it does you should be ok. I'm not sure how attached you are to your down bag, but a synthetic bag of equal temp rating should keep you just as warm (even when soaked with sweat, water, beer, whatever). And the weight difference isn't all that noticable.

 

Another little tip for sleeping/keeping warm at altitude: Eat something before you go to sleep - this keeps your metabolism going for a while, and thus your body is generating heat longer.

[Dhamma]

thanks a lot for answering my question man i appreciate it. i was wishing i had a synthetic bag when i had a soggy cold bag up there. im considering ebaying it

[tvashtarkatena]

Don't Ebay your down bag and downgrade to a POS synthetic one. Get a proper bivvy sack or a silnylon tarp when rain is possible.

 

 

[Dhamma]

the last time i bivy sacked it in this 15 deg bag i woke up with the footbox soaking wet too..... not a problem for one night trips, but for multi-day makes me a bit leery