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Ashley Brown
(ashleyb) - F
base + MB inner + rain jacket = ? (min temp) on 01/07/2009 19:09:05 MST Print View

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).

Ben 2 World
(ben2world) - MLife

Locale: So Cal
Re: base + MB inner + rain jacket = ? (min temp) on 01/07/2009 19:47:06 MST Print View

For sitting around camp, the combo is good for me down to mid 40's.

Ashley Brown
(ashleyb) - F
Re: Re: base + MB inner + rain jacket = ? (min temp) on 01/07/2009 19:49:14 MST Print View

Thanks Ben. What do you add when it gets colder?

Ben 2 World
(ben2world) - MLife

Locale: So Cal
Re: base + MB inner + rain jacket = ? (min temp) on 01/07/2009 19:52:05 MST Print View

I have a heavier MB Thermawrap (the next level above the UL Thermawrap) which I bring for temps down to freezing.

Tad Englund
(bestbuilder) - F - MLife

Locale: Pacific Northwest
Re: base + MB inner + rain jacket = ? (min temp) on 01/07/2009 20:49:17 MST Print View

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.

Craig W.
(xnomanx) - F - M
Re: Re: base + MB inner + rain jacket = ? (min temp) on 01/07/2009 21:12:04 MST Print View

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...

Bradford Rogers
(Mocs123) - MLife

Locale: Southeast Tennessee
Thermawrap on 01/07/2009 21:34:31 MST Print View

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.

Mike W
(skopeo) - F

Locale: British Columbia
base + MB inner + rain jacket on 01/08/2009 00:50:46 MST Print View

I add a MB U.L. Down Inner Vest over my Thermawrap to extend the range down to freezing temps. My arms will feel the cold but I will be comfortable. I also find that adding rain pants really adds some warmth as the temp drops especially if there's a breeze.

Edited by skopeo on 01/08/2009 02:03:20 MST.

Lynn Tramper
(retropump) - F

Locale: The Antipodes of La Coruna
Re: base + MB inner + rain jacket on 01/08/2009 13:14:51 MST Print View

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!

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
A mouse and a horse on 01/08/2009 14:46:25 MST Print View

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.

Joshua Gilbert
(joshcgil2) - F

Locale: Seattle
Re: a mouse and a horse on 01/08/2009 15:02:58 MST Print View

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?

Tyeen Taylor
(TyMaz) - F

Locale: Alaska
Need one more layer on 01/08/2009 15:39:02 MST Print View

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.

John Myers
(dallas) - F - MLife

Locale: North Texas
Base+MB+FT on 01/08/2009 15:48:55 MST Print View

Ashley,
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.

Lynn Tramper
(retropump) - F

Locale: The Antipodes of La Coruna
Re: A mouse and a horse on 01/08/2009 16:37:23 MST Print View

>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.

Edited by retropump on 01/08/2009 16:38:35 MST.

Jamie Shortt
(jshortt) - MLife

Locale: North Carolina
base + MB inner + rain jacket = ? (min temp) on 01/08/2009 16:57:13 MST Print View

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)
*Fleece Cap

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.

Jamie

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: A mouse and a horse on 01/08/2009 18:46:06 MST Print View

> 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.

Cheers

Lynn Tramper
(retropump) - F

Locale: The Antipodes of La Coruna
Re: Re: Re: A mouse and a horse on 01/08/2009 18:59:35 MST Print View

>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!

Richard Nisley
(richard295) - M

Locale: San Francisco Bay Area
Re: Re: Re: Re: A mouse and a horse on 01/08/2009 23:04:58 MST Print View

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…

Edited by richard295 on 01/08/2009 23:06:09 MST.

Lynn Tramper
(retropump) - F

Locale: The Antipodes of La Coruna
Re: Re: Re: Re: Re: A mouse and a horse on 01/09/2009 01:57:02 MST Print View

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???

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Re: Re: A mouse and a horse on 01/09/2009 02:43:34 MST Print View

Hi Richard

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.

Cheers