So I have this old Slumberjack sleeping bag I got from Pack & Paddle in San Dimas about 1980. When I got it at that time everyone said you should not layer when you are in your sleeping bag. The thought was your body has to heat up all the cloths and the bag never gets warm. I dont know if it was the Hollofil 2 filling or if it applied to every bag. I just got a new bag because the slumberjack is too short for me, and Im seeing people talk about wearing layers to bed. What gives? This bag is "rated" to 20° and Im wondering if that means in your thermals or with layers.
New sleeping bag and my old REI external frame pack, its gonna be a good summer!
Layering in a sleeping bag?
If you're cold in your sleeping bag, add layers. The goal is to provide adequate insulation to sl;eep comfortably. For example, in a 35 F rated bag in mid-teens temperatures, I'll wear long underwear, wool socks, and a wool cap. However, I usually try not to wear all my clothes so that when I leave the relative shelter of the tent for the generally colder outside environment I have another couple layers to add so I'm comfortable outside.
Most sleeping bags are rated temperature rated for an "average" person inside a tent so bivouac conditions, wind, base metabolic rate, and personal preference can affect how you perceive the rating of a sleeping bag.
Of course, I go the other way with the 35 F bag and 70 F nighttime temps...
Most sleeping bags are rated temperature rated for an "average" person inside a tent so bivouac conditions, wind, base metabolic rate, and personal preference can affect how you perceive the rating of a sleeping bag.
Of course, I go the other way with the 35 F bag and 70 F nighttime temps...
if i didn't layer in a sleeing bag, i'd be dead by now. i once spent nights shivering in my bag, but i think either i have gotten the hang of the best layering for me or have finally acclimated to cold temps.
i returned a 10 degree rated REI down bag when i spent 3 nights freezing cold on Kilimanjaro with every layer i brought on my body. i now own a -0- degree Marmot Lithium bag and have slept on my last two snow camps with a pair of socks, my Arcteryx long underware bottoms, a silk long sleeved top with a medium weight top and my Montbell down jacekt on. I usually start with a fleece hat and light gloves but sometime during the night shed both the hat and gloves. last week i noticed that at 5am my legs were cold so i put on my hiking pants (a pair of Patagonia guide pants) until i got up. i also use a silk sleeping bag liner. i notice i sleep colder than the guys i snow camp with. i don't know if this is average for a woman, but i would rather shed layers if i become warm during the night then spend a another sleepless night too cold. i learned the hard way that saving $100 is not worth it when you suffer through 8-10 hours miserable, shivering and awake knowing that you have an epic day of hiking/climbing ahead of you and wondering how the heck you are going to do it on no sleep.
i also use Thermarest Z-lite and Prolite Plus pads in the winter.
in the summer i have a lighter bag, use one pad and a lot lighter clothing while sleeping.
i returned a 10 degree rated REI down bag when i spent 3 nights freezing cold on Kilimanjaro with every layer i brought on my body. i now own a -0- degree Marmot Lithium bag and have slept on my last two snow camps with a pair of socks, my Arcteryx long underware bottoms, a silk long sleeved top with a medium weight top and my Montbell down jacekt on. I usually start with a fleece hat and light gloves but sometime during the night shed both the hat and gloves. last week i noticed that at 5am my legs were cold so i put on my hiking pants (a pair of Patagonia guide pants) until i got up. i also use a silk sleeping bag liner. i notice i sleep colder than the guys i snow camp with. i don't know if this is average for a woman, but i would rather shed layers if i become warm during the night then spend a another sleepless night too cold. i learned the hard way that saving $100 is not worth it when you suffer through 8-10 hours miserable, shivering and awake knowing that you have an epic day of hiking/climbing ahead of you and wondering how the heck you are going to do it on no sleep.
i also use Thermarest Z-lite and Prolite Plus pads in the winter.
in the summer i have a lighter bag, use one pad and a lot lighter clothing while sleeping.
Thanks for the info. I just remember being taught that the more you have on you never actually warm up your bag. Your body wont heat all the layers and get heat into the filling in the bag. Maybe things have changed just like dont eat avocados, eat avocados, or the "you will go blind" thing. 
I laid out in my back yard about 7:30 last night and it was 38° and wind was blowing about 8-12 mph. I just had cotton socks on, shorts and a tshirt and I was laying on a cheap blue pad and I was warm
I was shocked because I was use to an old 5.5 lbs bag that was as big as a country fair watermelon, and this thing is 3 pounds and the size of a football. Its just a Alps mountaineering 20° bag that was on clearance at REI for $45. I am going to use it more as a 3 season, not really doing any snow stuff for a long time. And I was afraid of the "get what you pay for thing", but so far it seems ok.
I laid out in my back yard about 7:30 last night and it was 38° and wind was blowing about 8-12 mph. I just had cotton socks on, shorts and a tshirt and I was laying on a cheap blue pad and I was warm
I was shocked because I was use to an old 5.5 lbs bag that was as big as a country fair watermelon, and this thing is 3 pounds and the size of a football. Its just a Alps mountaineering 20° bag that was on clearance at REI for $45. I am going to use it more as a 3 season, not really doing any snow stuff for a long time. And I was afraid of the "get what you pay for thing", but so far it seems ok.
Layering will help extend the range of the sleeping bag below its intended rating to a small degree.
The biggest considerations are having a proper R value pad(s) under you for the conditions and a properly EN tested bag for men & women. Note that women generally require 5-7*F lower rated bags than men.
For example, if you choose a EN tested 30*F bag rated for men and you are a woman, the comfort limit would be in the 35-37*F range with a proper R value pad underneath. But if you find an EN tested 30*F bag rated for women and you are a woman then you can expect it to function at 30*F for its comfort limit.
The good thing about the EN system is that if you are a man and can fit into a women's bag, then your EN comfort rating will be 5-7*F lower than the tested rating. EG 30*F women EN tested is comfort limit from 23-25*F for a man.
The EN testing is done with a 5.0 R value pad and is generally good down to 30*F temps for the comfort limit. The bad thing about EN testing is that they do not increase the R value on the pad below 30*F, so the accuracy of the test at 0*F and below gets slightly skewed in the wrong way due to the lower insulation pad being used with the test.
Of course every person is different and some people are "warm" sleepers and others "cold" sleepers and would need to get different rated bags based on their sleep comfort.
The biggest considerations are having a proper R value pad(s) under you for the conditions and a properly EN tested bag for men & women. Note that women generally require 5-7*F lower rated bags than men.
For example, if you choose a EN tested 30*F bag rated for men and you are a woman, the comfort limit would be in the 35-37*F range with a proper R value pad underneath. But if you find an EN tested 30*F bag rated for women and you are a woman then you can expect it to function at 30*F for its comfort limit.
The good thing about the EN system is that if you are a man and can fit into a women's bag, then your EN comfort rating will be 5-7*F lower than the tested rating. EG 30*F women EN tested is comfort limit from 23-25*F for a man.
The EN testing is done with a 5.0 R value pad and is generally good down to 30*F temps for the comfort limit. The bad thing about EN testing is that they do not increase the R value on the pad below 30*F, so the accuracy of the test at 0*F and below gets slightly skewed in the wrong way due to the lower insulation pad being used with the test.
Of course every person is different and some people are "warm" sleepers and others "cold" sleepers and would need to get different rated bags based on their sleep comfort.
Saying that layering in your bag is going to make you somehow cold is like saying you're going to get cold if you put on a shell over your fleece. What a load of malarkey.
When wearing a down sweater, I've slept down to the mid 20's in a 32F rated bag and been quite comfortable -- and I'm a cold sleeper. There's no way I could have done that without layering in the bag.
The only time you might get cold with more layers is if the extra layers caused compression of the insulation of the sleeping bag. As long as there's room enough for extra layers, extra layers will keep you warmer.
EN ratings are nice -- if you can find bags that have been put through the testing. EN ratings are a European thing, and so not all bags available in the US have gone through the testing. As for US ratings, there are no standards, and so manufacturers are free to claim whatever they like. Some brands, like Western Mountaineering are known for solid ratings. The claims of some other brands, like Coleman, verge on outright fraud.
HJ
When wearing a down sweater, I've slept down to the mid 20's in a 32F rated bag and been quite comfortable -- and I'm a cold sleeper. There's no way I could have done that without layering in the bag.
The only time you might get cold with more layers is if the extra layers caused compression of the insulation of the sleeping bag. As long as there's room enough for extra layers, extra layers will keep you warmer.
EN ratings are nice -- if you can find bags that have been put through the testing. EN ratings are a European thing, and so not all bags available in the US have gone through the testing. As for US ratings, there are no standards, and so manufacturers are free to claim whatever they like. Some brands, like Western Mountaineering are known for solid ratings. The claims of some other brands, like Coleman, verge on outright fraud.
HJ
I was in A16 last night - noticed they had a couple WM bags on the wall. They look so nice, my Big Agnes 0 Degree bag looks like garbage compared to the 5 Degree WM model I was checking out. It cost me about half as much, though. Yikes.
Yeah, WM is kinda high end. Go eBay. I've gotten a couple of WM items that way.
HJ
also good points. I forgot to mention compressing the down will have a negative effect that Jim pointed out.Hikin_Jim wrote: ↑Saying that layering in your bag is going to make you somehow cold is like saying you're going to get cold if you put on a shell over your fleece. What a load of malarkey.
When wearing a down sweater, I've slept down to the mid 20's in a 32F rated bag and been quite comfortable -- and I'm a cold sleeper. There's no way I could have done that without layering in the bag.
The only time you might get cold with more layers is if the extra layers caused compression of the insulation of the sleeping bag. As long as there's room enough for extra layers, extra layers will keep you warmer.
EN ratings are nice -- if you can find bags that have been put through the testing. EN ratings are a European thing, and so not all bags available in the US have gone through the testing. As for US ratings, there are no standards, and so manufacturers are free to claim whatever they like. Some brands, like Western Mountaineering are known for solid ratings. The claims of some other brands, like Coleman, verge on outright fraud.
HJ
I also have a WM bag (sycamore) that is not EN rated but is known for being true to their ratings and is listed by the manufacturer at 25*F. I generally sleep with midweight wool bottoms midweight wool top and a synthetic beanie and i'm good down to the listed rating. I usually just wear shorts and a T in 30-40*F.
I also have a marmot trestles that is EN tested with a comfort limit of 49*F for men, and have been in the upper 30*F with a good amount of layering on and a 4.9R value pad underneath and been comfortable.