Jan 7, 2009 at 6:09 pm #1233084
I'm interested in hearing from folks who use the combo of a baselayer + montbell UL down inner jacket + rain jacket shell for sitting around in camp. What sort of temps are you comfortable down to? 35F? Or is that pushing it? (assume you're wearing hat and gloves, and normal hiking pants on your legs).Jan 7, 2009 at 6:47 pm #1468624
Ben 2 WorldParticipant
@ben2worldLocale: So Cal
For sitting around camp, the combo is good for me down to mid 40's.Jan 7, 2009 at 6:49 pm #1468625
Thanks Ben. What do you add when it gets colder?Jan 7, 2009 at 6:52 pm #1468627
Ben 2 WorldParticipant
@ben2worldLocale: So Cal
I have a heavier MB Thermawrap (the next level above the UL Thermawrap) which I bring for temps down to freezing.Jan 7, 2009 at 7:49 pm #1468639
@bestbuilderLocale: Pacific Northwest
Last October I was on a hike and the temp at the trail head was 29* at 5:00 pm. I hiked in a light weight long sleeve merino wool 1/4 zip t-shirt and a Montane Litespeed windshirt, regular hiking pants. After arriving to our campsite, in the dark the temp was 24*. I put on my Montbell inner under my windshirt and a OR fleece windstop cap, and fleece gloves. I did add long johns to get ready for bed a little earlier then normal.
I was warm and comfortable with the above on, though I was only standing around and cooking for about 1 1/2 hours before going to bed.Jan 7, 2009 at 8:12 pm #1468647
I've been comfortable in the high 20's with a polypro longsleeve base, synthetic t-shirt, MB Thermawrap, and a Marmot Ion.
I assume the down is only warmer than the Thermawrap.
This is a pretty subjective question though…I think you'll find a range of 10-15 degrees from person to person.
I say go with the minimum you think you'll need- worst case, just get your bag/quilt out and wrap it over your shoulders and onto your lap- perfectly fine if you're just sitting around.
Amazing how many times I've seen people sit and shiver in camp when they have a super warm sleeping bag 10 feet away from them…Jan 7, 2009 at 8:34 pm #1468653
@mocs123Locale: Southeast Tennessee
I have been comfortable in the low to mid twenties with a lightweight Capaline Baselayer, a Patagonia R1 Pullover, the Montbell Thermawrap, and a Golite Phantom Rain Jacket.
I assume the Down Inner Jacket would provide at least as much warmth as the Thermawrap.Jan 7, 2009 at 11:50 pm #1468666
@skopeoLocale: British Columbia
…Jan 8, 2009 at 12:14 pm #1468739
I'm OK down to freezing with a base layer, microfleece top and UL down inner with windshirt or rainjacket over the top (plus windblock hat and gloves). This is if it's calm. If it's very windy this won't be enough for me. But the person-to-person variation is really quite large!Jan 8, 2009 at 1:46 pm #1468760
Clothing questions posed and answers provided to the BPL forum are of inconsequential value without specifying a MET level and, to a lesser degree, duration. The difference in everyone’s BMR (resting energy / body surface area) varies less than 20%. In other words it is not correct that "..the person-to-person variation is really quite large". What is large is that your MET level (activity energy/ resting energy) varies ~1,500%.
BMR is expressed as energy per unit of body size per unit of time. The classic table of Voit (1901) giving the heat production of resting animals of varying sizes in a thermo neutral environment shows clearly that the energy expenditure ranges from 212 kcal/kg/day for a mouse to 11 kcal/ kg/day for a horse – a 20-fold difference – whereas expressed per m2 of surface area the range is from 1200 kcal/day for the mouse to 950 kcal/day for the horse, and values for the other animals, including man, are within about ±20% of the mean for the group.
The big variable is the MET value (multiplier of the BMR based on the activity level) and the duration of the activity. This is what primarily determines the amount of clothing insulation you need.Jan 8, 2009 at 2:02 pm #1468766
Richard, could you express that in laymans terms? what is BMR, MET, etc., and what are the implications of what you are saying for the thread?Jan 8, 2009 at 2:39 pm #1468775
Inconsequential? Yikes, now I'm nervous.
I add a Patagonia Cap 4 zip OR Icebreaker Bodyfit 260 zip to the three layers assumed in this discussion. Even with that I sometimes have to do a little dance when I get out of my tent in the morning (but i like dancing so its cool). My playground is interior Alaska which has a wide range of temps even in the peak of the summer. Alpine can see 70 degree days and snowy nights, but that's what makes it fun! If I know I'm camping below tree line I nix this additional layer.
The whole system is used all at once less than %12 of the trip, but carrying the extra 9 ounces is well worth not being chilled in my opinion.Jan 8, 2009 at 2:48 pm #1468779
@dallasLocale: North Texas
My experience with a Capilene 2 base layer, MB UL down jacket, Frogg Toggs rain jacket and Turtlefur balaclava is that I am comfortable down to 35 degrees sitting around camp. I get overheated hiking in that gear at 35 though.Jan 8, 2009 at 3:37 pm #1468786
>The big variable is the MET (metabolism) value (multiplier of the BMR based on the activity level) and the duration of the activity. This is what primarily determines the amount of clothing insulation you need.
Yeah, obviously the longer and/or higher you exertion levels, the more heat you will generate. For *most* of us, keeping warm while moving with a pack on is not the problem though. For me the biggest time when I need insulation is after I've stopped moving…just sitting around waiting for dinner to cook and stuff. And there's also a clear gender difference as men really (in general) run hotter than women. Fat insulates, muscle generates heat as well. So there really are a lot more variables than just overall metabolism. BMR becomes more important at 3am on a frosty morning when you are regretting not bringing a warmer bag (or down jacket in this case), while your partner next to you in the same style bag is sleeping warm as a bug in a rug.Jan 8, 2009 at 3:57 pm #1468792
@jshorttLocale: North Carolina
Here is my clothing system that I use down to 20 degrees. It is pretty much "base+MBinner+rain jacket". The only other thoughts I would add is my coldest temps are always in the morning right at sunrise. It is not at night. It takes a while for temps to drop until after dark and by then I'm in my bag (even in winter).
*REI Lightweight MTS Long-Sleeve Zip-T
*Columbia Silver Ridge Convertible Pants
*Golite Virga Jacket
*Mont-Bell UL Down Jacket
*REI Oslo Gloves (90/10 Poly/Wool)
As it has been pointed out, wind will greatly influence this. A few weeks ago the temps dropped to 25 degrees and the wind was driving from 20-50 mph on a ridge top. I had to wear everything listed to stay warm "while hiking". I was cold if I stopped.
JamieJan 8, 2009 at 5:46 pm #1468816
@rcaffinLocale: Wollemi & Kosciusko NPs, Europe
> For *most* of us, keeping warm while moving with a pack on is not the problem though. For me
> the biggest time when I need insulation is after I've stopped moving…just sitting
> around waiting for dinner to cook and stuff.
Yep, agree entirely.
However, I do think that there is a psychological factor as well. OK, it may be part psych and part physiology actually – or you could just call it 'cold adaption'. We were up in the mountains wearing a single Taslan layer top and bottom (our normal Taslan clothing), while the people with us who were not 'mountain-experienced' were wearing fleece trousers and fleece jackets.
At a technical level, it may be that our bodies were used to holding a slightly elevated metabolic rate while also allowing skin surface temperature to be lower than normal.
Clearly, if what I am saying is correct, then people are going to have very different clothing requirements, with 'outdoors experience' playing a significant role.
CheersJan 8, 2009 at 5:59 pm #1468819
>At a technical level, it may be that our bodies were used to holding a slightly elevated metabolic rate while also allowing skin surface temperature to be lower than normal.
I have observed this as well, and not just in the mountains. There is that shock at the end of autumn when you get the first really cold days of winter, and then as winter drags on you find yourself more and more comfortable with the lower temps. It is particulalrly evident in people who move here from tropical climates. It seems almost as if sometimes they never completely adapt to the colder temps, as if growing up in a warmer climate has permanently changed their thermostat!Jan 8, 2009 at 10:04 pm #1468863
Unlike adapting to high heat, most people don't have good short term adaptation mechanisms for cold. The cold adaptation mechanism takes 2-5 weeks of exposure to occur on average.
The difference in the heat production between individuals in either the acclimated or non-acclimated groups is small compared with the differences resulting from various post backpacking camp activities. In contrast with the typical 20% variation between individuals, the variability in post backpacking camp activities is ~ 250%. The specific heat capacity of the body buffers the various MET heat levels similarly to the way merino wool buffers moisture transport. This is the reason the specific camp activities and the duration of the camp activities are both relevant.
There seems to be a large number of the BPL forum participants who believe we are each so unique we each need different insulation amounts for the same MET level. It strikes me as strange, that in contrast, the large number of Natick scientists supporting the selection of sleeping bags and clothing for the millions of people in the US Armed Services conclude the exact opposite. Maybe if we see something repeated enough in the BPL forums we assume it must be true? Maybe it is related to the fact that INTJ make up a very small percentage of the population and yet the majority of the forum participants have this personality profile? Maybe…Jan 9, 2009 at 12:57 am #1468873
Richard, you may most likely be right of course, becaus science (the US armed services and sleeping bag manufacuters) can't be wrong. But as a middle-aged (scientifically minded) women undergoing the drawn-out passage into menopause, I am accutely aware of the importance of hormones AND perception involved in feeling warm or cold in any environment. Menopausal women don't run any warmer than their younger counterparts, their thermostats just goes haywire so they THINK they are burning up, without using any mor calories or producing any more heat than younger women. And that's just one example where the Briggs-Myers classification is totally not relevant to one's perceived warmth in a given situation. If Briggs-Myers and the military had as their first questions "what is your gender and your age" followed by "what climate were you born and raised in, then their conclusions may have been very different…And how does personality account for the overwhelming number of people from the tropics that "just feel cold" in an environement where I (and many others) are down-right boiling???Jan 9, 2009 at 1:43 am #1468876
@rcaffinLocale: Wollemi & Kosciusko NPs, Europe
I think we may be talking about two different things here. There is a genuine physiological adaptation to cold which may even have a racial component, and there is the psychological adaptation. The latter is the difference between an experienced mountaineer and a 'tourist'. The mountaineer knows he is OK with just a light shirt, while the 'tourist' senses the cold and thinks he might freeze to death.
It can go beyond this, with the experienced mountaineer being happy to have his skin surface temperature way below that of the tourist. With a lower skin temperature heat loss actually drops, as the consequent vasoconstriction limits the amount of heat going to the surface.
> the large number of Natick scientists supporting the selection of sleeping bags
> and clothing for the millions of people in the US Armed Services
Well, yes, but there may be a difference between a small number of highly motivated and experienced mountaineers on the one hand and thousands (millions?) of young inexperienced pRegulars in the Army. There may even be some self-selection in the mountaineer group in favour of the ability to handle the cold; a self-selection process which we can be reasonably sure does not happen in the armed forces.
CheersJan 9, 2009 at 6:00 am #1468885
One tenant of UL Backpacking is that it is always lighter to carry knowledge rather than physical things that can be obviated by that knowledge. The “horse and mouse” basal metabolic rates provide knowledge relative to our requirements for clothing insulation. The variation between individuals is in the range of 20% once the variance in body surface area is adjusted for. The difference in our respective body surface areas is automatically compensated for by all reputable UL clothing manufactures. For example, a Skaha Plus Down Sweater with Front Pocket increases the down amount in proportion to the body surface area increase. A size XS = 3.75 oz, S = 4 oz, M = 4.5 oz, L = 5 oz, XL = 5.5 oz, and XXL = 6 oz.
A bigger individual difference in insulation required occurs, for example, “whether you stand or sit while eating your dinner”. Clothing insulation requirements are inversely proportional to the MET rate (the amount of heat you are generating in an activity / the amount of heat you are generating with resting). It is common place for a 250% variance in MET rates when UL backpackers say they are inactive.
The importance of cold acclimatization in providing the individual with an advantage in coping with the environment is much less than with the acclimatization humans exhibit in response to chronic heat exposure. There is some sensory acclimatization–after long exposure it bothers us less. Habituation improves comfort and dexterity as well as reducing susceptibility to cold injury, but overall, the advantage provided by cold acclimatization, in terms of conservation of body heat and defense of body temperature, is considerably less than can be derived from modern protective clothing.
In summary, if you really want to understand the thermal effectiveness of various clothing ensembles, focus on the BPL forum contributors that specify the allocated times and MET rates that led to their custom comfort ratings. They are the ones offering you the most valuable information.
PS: I wrote this up last night prior to reading the new posts today. Roger – We are in agreement. Allison – Good questions about cold acclimatization. I will look into to this and hopefully get back to you shortly.Jan 9, 2009 at 6:39 am #1468890
"In summary, if you really want to understand the thermal effectiveness of various clothing ensembles, focus on the BPL forum contributors that specify the allocated times and MET rates that led to their custom comfort rating. They are the ones offering you the most valuable information."
Problem is…I have no idea whatsoever how calculate MET and BMR, let alone a good grasp of what they even are.
Turning this into an experiment in math and science is one way to go…but I'm not sure we need to get that complicated.
Another way that has generally worked for me (despite some variations in individual comfort levels) is this:
"Duuude, what did you wear on that gnar climbing trip you did?"
"The Patagucci Superduper MX914.5 Ultralight Spacemonkey Jacket."
"How cold was it?"
"I dunno, like 30 degrees."
"Were you warm chillin' in camp?"
"Cool. I think I'll pawn my hooka and go buy one."
As I said earlier, if you blow it and find yourself a little cold in camp, throw your sleeping bag on. Drink something hot. Have some more whiskey. Do 50 jumping jacks and return to the conversation.
I never got the impression we were talking life and death here, but simply how to stay comfy while sitting around camp.Jan 9, 2009 at 7:01 am #1468891
I think the idea is to include something about effort and duration, as well as temperature, wind, and sunshine:
"Uphill at a barely-can-talk pace for 3 hours…"
"Good trail over rolling terrain, talking all the way…"
Some can actually state "All day at 10 beats below lactate threshold…"
(I believe this is also useful when considering minimum food requirements.)
The important point is to summarize something about total "output". That way I might be able to relate that what kept you warm in a given situation would keep me warm. And then I could factor in the whiskey or jumping jacks.Jan 9, 2009 at 7:44 am #1468895
Check out the original post.
I think this has has quickly become a case of "science" not allowing people to see the forest for the trees.Jan 9, 2009 at 8:36 am #1468914
Roger >I think we may be talking about two different things here. There is a genuine physiological adaptation to cold which may even have a racial component, and there is the psychological adaptation.
Richard>The cold adaptation mechanism takes 2-5 weeks of exposure to occur on average.
The cold adaptation Richard is talking about, is it same as psychological adaptation? Is there a re-adaptation period everytime you are in cold climate after spending a sometime in hot climate or is understanding and experience that is important.
>It can go beyond this, with the experienced mountaineer being happy to have his skin surface temperature way below that of the tourist. With a lower skin temperature heat loss actually drops, as the consequent vasoconstriction limits the amount of heat going to the surface.
What I'm really asking is does adaptation mean understanding the above and experiencing it so you are confident?
Since last few days I have started practicing this adaptation. It get a bit chilly at night, and normally I would use a quilt and get cosy. But what I do now is lock-up my quilt in the cupboard and put the keys away, so I dont sneak up in middle of night and get the quilt out. :) I am going for a hike next week and I am really excited about how it will work out without insulation.
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