Wicking, yay, nay, or "it's relative" to the importance?

Matt D. wrote, “Justin, in this particular scenereo (extreme cold and wet), evaporative cooling IS NOT the primary form of heat loss. If your base/mid layers are saturated from sweat, and your outer layer has wetted out, the greatest risk is from simple conductive cooling directly to the outside air. I believe this is what Eric is saying. Cold humid is the worst, since the air itself is saturated and there’s no room for evaporation to occur. The cold humid air is effectively an energy conductor.”

Contrary to Eric’s constant insinuations, i’m basing this on repeat experience.  I hike primarily from late Fall to early Spring.   I’ve been out in sub zero temps and very wet, lots of freezing rain and, hovering near freezing temps.  I have tried various different baselayers in those (and other) conditions (desert, tropical, etc).

I have noticed that in both very cold and extremely dry, and in cold and wet conditions, that i feel most comfortable when i wear a Cap 4 type baselayer or a fishnet.  I have 3 fishnets btw.  A polypropylene one, a nylon-spandex one, and an Alpaca-Synthetic knit blend that a friend made for me.  I have not yet tried the last one, because i received it after the cool weather ended this Spring.   It’s also much heavier than i would have liked.

In some ways i most prefer the polypropylene fishnet over the other pieces.  Why, because i know that i could fall into a creek, or get completely soaked from cold rain, and that piece would always provide me a nice layer of semi-dry air.   It absorbs practically no moisture.

Since it does not wick much at all, the comfort can only be explained by a combination of the following.  PP has the lowest thermal conductivity of any commonly worn fabric type material, it’s extremely hydrophobic, there aren’t enough fibers and fiber interstices to absorb appreciable amounts of moisture, and it constantly maintains a thin, insulating air layer directly on the skin.  It allows evaporation directly from the skin, which imo, regulates it somewhat, especially when it’s very cold and very dry.

I’ve experienced first hand what Ryan Jordan has written about as far as flash freeze with traditional, thin, very well wicking and very quick drying polyester baselayers.  I was out one time for a weekend trip when the high was around 10F on Sunday, and when still hiking in the early morning (so like temps from 3 to 6), with moderate wind, i could feel the cold wind go through my windjacket, my thin mid layer, and to my baselayer, and even though i was trying to regulate my sweating, my back was (and is pretty much always) soaked because of my pack.    When i took my pack off at rests, i became very chilled.  It seems that the thin, very well wicking, quick drying poly baselayer was drying fast enough to really lower the temp of the material and air/water next to it.

I have not experienced similar with Cap 4, Fishnets, nor Merino-synthetic blends.  For the first two, what explains that to me, is the greater air gap, and for the latter, the slower, less efficient, different and non “spreading” wicking that Merino does. Also, Merino is a good all around insulator in general. However, i don’t like that the Merino, even when blended with synthetic, can get to the point of feeling a bit soggy (especially when it’s cool and very humid and wet).  So while i like the odor reduction, i prefer the overall comfort of Cap 4 and fishnet in that regard.

Have you or Eric extensively used fishnets?  If not, i recommend giving them a try.  The Norwegian Military has made fishnet baselayers their standard issue baselayers   The Nords know a little something about cold conditions, both extreme and very dry cold, and very wet, humid cold, depending on where you are in Norway or Scandinavia in general.

I would say that in this area, Eric is the one speaking from a lack of experience.  If Polyproplene didn’t get so dang stinky, it would be my favorite cold weather (whether very dry or wet) baselayer hands down.  That’s why i really want to try my Alpaca-Synthetic blend fishnet, because i suspect it will be near as comfortable as the PP one, but without the stink (Alpaca and Merino have similar properties when it comes to odor reduction, but Alpaca doesn’t absorb as much moisture and has stronger tensile strength per individual fiber).

I hope this thorough explanation based on my experience helps to clear up things a bit.  If folks don’t believe me, i suggest trying these different pieces in the similar varied conditions that i’ve outlined.   As mentioned previously, or on another thread–when in Costa Rica, when active, the only thing that kept me semi comfortable and not completely soaked, was the thin, very breathable, well wicking OR Echo shirt.

I should add that in those cold (both very dry/extreme cold and wet) conditions outlined, i actually like to wear a wicking, quick drying baselayer as my mid layer or directly over the Cap 4 or fishnet baselayer.  Since i run warm, the combo of these, with a windjacket and/or rain gear, can do me good in a wide range of temps and conditions when active.  I have also worn 100 wt type fleece.  For very cold or very wet and cool/cold conditions, i might combine the above with a regular or grid fleece vest with the back cut out, or my very breathable 2.2 oz/yd2 Apex, front only insulated vest.

I like to think outside the box.

IMO, wicking layers or whatever we want to call them are indispensable in cold weather where moisture is pushed out from the body. We want to try and maintain an equilibrium over varying terrain. We are not static when traveling, so some of the previous explanations are more theory than reality to me. For example, earlier this year I did about 20 miles in temps right around freezing with constant light wind, but no rain or snow. Sections of the route had elevation gains between 500′ to 1,000′ per mile. Other sections were fairly flat and others had considerable elevation loss. I wore a Cap 4 grid over a Cap 1 short sleeve T-shirt and a Houdini. Ex-Officio Give-n-Go briefs under Schoeller trousers, thick wool socks and trail runners. On the uphills I would open the 1/4 zipper on the Cap 4 and partially on the Houdini. The rest of the time the zippers were mostly zipped up. Rest stops required a down jacket. I was comfortable all day. I do agree with Justin W that polypropylene is the best wicking material, and it is the stinkiest. I had a lot of it decades ago.

In hot weather, ventilation is king. Typically I wear Patagonia Baggies with the liner cut out, no underwear, no shirt, wool socks, and trail runners. I don’t want wicking, I want ventilation.

If I don’t have a good tan, I will wear a well ventilated T-shirt that is very loose. You need the air space under the shirt to keep coolest. The best ventilated shirts I ever had were purchased from REI in the early 80’s and were 100% polyester. I had a boatload of them and some were 1/4 snap T’s and some were tank tops. I only have one left (see the blue shirt below). I have replaced the worn out REI shirts with basketball type shirts that are similar. In really hot weather up to around 105F, when I wear a shirt, I now usually wear a Rail Riders eco-speed T, which is a poly-nylon blend, a fairly open weave. It is the shirt on the right in the picture below.

The picture below shows the ventilation as I placed a 8″ X 11″ piece of paper under the material.

The picture below shows the eco-speed T with the same piece of paper under the fabric. You can see the side mesh panels are much more ventilated than the front and back of the shirt.

Common advice is to wear light colored clothing in deserts, however I find dark colors keep me cooler when resting in the shade, and the blue REI shirt is perfect.

When temperatures are above 105F up to 120F, I prefer a thick cotton T shirt because they slow down the evaporation. Decades ago I used JC Penny Towncraft crew T’s which haven’t been available in years. Recently I found these Pro Club heavyweight 6.5 ounce weight, 100% cotton T-shirts. Although I would normally wear a medium, I bought size XL, to ensure they are very loose. I got a dozen for around $60. Keep in mind I am not going to hike all day in temps above 105F, I will seek shade and rest during the heat of the day.

The most difficult conditions for me are high heat and high humidity. 90% humidity and 90F temperature is much, much worse than 120F in the desert. But like in deserts, I use loose clothing that vents. Wicking does no good because moisture can’t evaporate in high humidity. The one exception is I will wear wicking underwear under my Patagonia Baggies to try and minimize the moisture as much as possible. Below is a summer trip with high heat/high humidity in Pennsylvania a few years ago, wearing Patagonia Baggies and an eco-speed T shirt. I had to wear the shirt to help fend off the mosiquitos.

With all of this, we must keep in mind that people are different, so there isn’t a universal solution. For example, the natives of Africa’s deserts wear little clothing vs the Arabs and Persians in the Middle East who drape themselves in loose fitting robes.

“I hope this thorough explanation based on my experience helps to clear up things a bit”

Thanks Justin, it does.

Now that I understand what you are referring to, the use of fishnet (I suspect like some of the Bryjne fishnet layering I’ve heard of before) does provide for a micro-air-gap between the surface of the skin and additional layer over top of it. Can’t say I’ve used it, (except for my Cap 4 – of course!)

I guess I would still interpret the “fishnet” method as another way to transfer moisture away from the body – through the use of multiple layers instead of a single base layer – woven with hydrophobic/hydrophillic material.

Like the research article I had mentioned before, they had concluded that the fabric they tested was most efficient at transporting moisture when the hydrophopbic side of was directly on the surface of the skin, with the hydropillic side facing out toward the shell. So the fabric is not simply spreading the moisture out directly against the surface of the skin, it’s pulling the sweat away, then spreading it.

Its essentially still a two part system, but in one layer.

Perhaps the fishnet acts as a large-scale hydrophobic layer, positioned to both move the sweat up into the layer over top of it, and evaporate some of it due to it’s air film. Regardless, you are more comfortable with it – and that’s most important.

Thank you Nick for sharing.  I also like cotton in the desert, well, actually last time i was out there, i wore some about half linen and half cotton shirts.

Sounds like a good summary Matt.

as promised, now that im home some actual links from journals and research groups …

less “BPL theorizing” …

http://nopr.niscair.res.in/bitstream/123456789/30112/1/IJFTR%2039(4)%20441-449.pdf

http://www.sasmira.org/sportwear.pdf

matt your article you referenced basically says similar things … what some of us has been saying all along … notably that the cap4 is made specifically with powerdry bicomponent fabric for wicking …

the science is pretty well known on the basics … im not quite sure what everyone is trying to figure out …

back to our regularly scheduled yapping …

;)

Your text says

“In severe sweating conditions, fabric next to the skin should not only absorb liquid quickly, but transport it through the fabric promptly to avoid discomfort of the fabric sticking to the skin”

So, wicking fabric will make you more comfortable, but not warmer

It’s not just marketing spin, there is value to wicking fabric

But, like I said, I found that wearing a wet shirt when it’s hot isn’t really that uncomfortable when I got used to it

It’s subjective.  If you like wicking shirts, great!

Some millennial women on the internets made some comment about their nickname for someone my age that didn’t wear a shirt on the PCT was “shirtless man”.  I don’t think they were being complementary.  Ever since, I’ve worn a shirt.  (99% humor – I don’t mind being the butt of someone’s joke if they get a healthful belly laugh out of it)

jerry …. in the cold wet base layers decreases the “warmth” (when its cold its also “comfort”) significantly

thats pretty basic stuff as quite a few BPLers have testified to … and its a really simple test as some of us have stated

if you dont believe me or them …

from the first study …

from a world leading expert in hypothermia about clothing in cold weather …

https://www.umanitoba.ca/faculties/kinrec/hlhpri/media/Cold_Weather_Clothing.pdf

as to going shirtless … i show off my ginourmous dim sum powered belly to the world with great pride!!!

;)

“…determines the comfort…”

again, that’s about comfort, not warmth

“…clothing insulation decreases during perspiration…”

but that doesn’t say anything about whether it’s better to have a wicking base layer.  If the water transports to a mid layer then it does it’s damage there

if you could transport water to the outer layer and then drip it onto the ground you’d make yourself warmer.  But if the water stays in the clothing and eventually gets evaporated, it doesn’t matter that much where the water got transported to.

Water in clothing reduces thermal insulation by as much as 30 – 50% due to conduction?  No.  Not enough water.  With the amount of water that would actually be in the insulation, it’s still 99% air so conduction isn’t an issue.  It’s just evaporation that’s an issue.

I’ve read places where they say conduction is significant, but never any technical data to back it up.

jerry …

you can argue it till the marmots get BBQed

its a VERY simple test in winter to have soaked layers if you dont believe me of the various BPLers who have also attested to it …

i and others here have posted links from published studies, research groups, the navy seal drills, and a world leading expert in hypothermia (“dr popsicle” if you want to google) …

unlike quite a bit of BPL theorizing ,this aint pseudoscience … its pretty well known and researched for quite a long time … which is why folks pushing the limits generally use modern garments that transfer moisture out

on BPL we can argue anything as its mostly just walking in milder conditions anyways … and anything will work

i mean we can “argue” that man didnt land on the moon as well … its all photoshopped

;)

Water in clothing reduces thermal insulation by as much as 30 – 50% due to conduction?  No.  Not enough water.  With the amount of water that would actually be in the insulation, it’s still 99% air so conduction isn’t an issue.  It’s just evaporation that’s an issue.

I’ve read places where they say conduction is significant, but never any technical data to back it up.

Jerry, you have many people (myself included) on this site, that you choose to visit, telling you that moisture against your skin in cold weather is a threat to cooling your body. you have anecdotal and experiential evidence from different people, climates, fabrics, etc… AND you have actual research (thanks Eric) that tells you specific values that validate everyone’s field observations (of course this varies with different fabrics, but that is not center of this debate). your response? you just say ‘No. Not enough water.’

(edited by mod, pls review)

jared …

“professor popsicle” is considered a leading expert on cold weather and submersion hypothermia …

he trains local SAR teams …

http://www.coquitlam-sar.bc.ca/2011/10/coquitlam-sar-and-dr-gordon-giesbrecht/

and he is not an ivory chair theory scientist … he tests everything himself

The masochism doesn’t stop there. In March 2001, to learn more about how the body metabolizes various energy sources in subfreezing temperatures, Giesbrecht and four other men each dragged 180 pounds of gear across the frozen surface of Lake Winnipeg, a body of water roughly the size of New Hampshire, for 19 days. Then there was that winter 1999 experiment during which, in an effort to cool his body core while keeping his skin temperature constant, he had a colleague inject, over a one-hour period, more than a gallon of nearly frozen saline directly into his bloodstream. “He’s a risk taker,” says William Forgey, a 60-year-old physician who is the past president of the Colorado Springs-based Wilderness Medical Society. “If he needs to take it to the edge, he does it himself. While the expertise is there and the risk is controlled, it’s still dangerous stuff. He’s like a race-car driver.”

There is, of course, a very good reason why Giesbrecht keeps getting behind the wheel: This winter, like every winter, athletes, adventurers, and hapless innocents will get themselves into trouble in the cold. While no organization keeps detailed statistics on cold-related deaths in the outdoors, each year hypothermia kills an estimated 700 Americans. An additional 1,800 or so are thought to perish in cold-water drownings.

Giesbrecht has devoted his academic career to improving the odds for such victims of exposure. He is Professor Popsicle, the King of Chill. He may have a cliché for every occasion—”Keep cool, but don’t freeze,” he’ll say, smirking like Mister Rogers—but he is one of a kind. Or at least a few: There are roughly a dozen scientists worldwide who specialize in human thermoregulation, the study of how the body responds to temperature changes. Only a handful undertake human experiments, and no one goes as far as Giesbrecht, who has intentionally taken his core temp lower—down to 88.2 degrees—than any other researcher. “I’m the scientist who does things for real,” he says, “to make sure I really know what I’m talking about.” 

more at link …

http://www.outsideonline.com/1821211/meet-prof-popsicle

not everyone agrees with his test protocols with human subjects (often himself) … but his combination of practical experience and research is undeniable

from his book … Hypothermia, Frostbite, and Other Cold Injuries: Prevention, Survival, Rescue, and Treatment

;)

moisture against your skin in cold weather is a threat to cooling your body.

Unless one one is wearing a vapor barrier you do not want moisture against your skin in cold weather. In my example, wearing a clothing system that can handle strenuous effort (hiking 1 mile with 1,000′ elevation gain) and then hiking on a flat or slight elevation loss, all without the need to remove or add layers, you need a system that can push or wick (choose your definition) moisture away from the skin without the clothing absorbing most of the moisture, and to move the moisture slow enough so it doesn’t create evaporative cooling. The combination of Cap 1, Cap 4, and a windshirt worked extremely well for the conditions.

Eric-

pardon any confusion. i know professor popsicle well…fascinating research. sure his human experimentation lends itself to some ethical debates, though i am a social scientist myself, so not much room to criticize his methods.

my previous post was edited by the man mod, but i was highlighting the credentials of the good professor, and his research and results, in contrast to the stubborn refusal of some posters to let go their long held beliefs in the face of overwhelming evidence in support of modern knowledge.

and now i will have a frozen coconut treat in his honor

I hate it went I start defending a position just because I don’t want to be wrong : )

I have James Wilkerson’s book “Medicine for Mountaineering”.  He is co-author of “Hypothermia, Frostbite, and other Cold Injuries”

One of Eric’s quotes says liquid water can be wicked to the outside and then evaporated.  That might be better because clothing will dry out if just hung to dry using ambient temperature.  But it’s slow.

In that quote, he said there must be a dry layer next to skin but doesn’t say why.

Regardless, a lot of people are happy Cap users, so that’s good.  It’s supposed to be more comfortable.

Here’s why I say conduction isn’t significant.  I should just ignore it when people say otherwise, but anyway.

I had a 12 inch square of synthetic insulation, Primaloft.  It was nominally 2 oz/yd2.  With breathable nylon on both sides.  0.5 inch loft.  It weighed 0.41 ounce.

I got it totally wet, then let the water drain out.  So this is as wet as it could get.  In typical use, it wouldn’t get this wet.  It weighed 1.34 ounces, so the water weighed 0.93 ounces.

0.93 ounces = 26.4 grams.  1 gram of water has a volume of 1 cm3 so the volume of water in my sample was 26.4 cm3.  The volume of the sample was 12.25 x 12.25 x 0.5 inches = 1229.5 cm3.  So the ratio of water to air/insulation in the sample 0.021.

The thermal conductivity (k) of air is 0.025 W/K/m.  Water is 0.596 W/K/m.

The worst case would be the water would be distributed as columns or planes from the front to the back surface.  The best case would be it would be distributed as planes parallel to the front and back surfaces.

For the worst case, the conductivity of the combined insulation and water would be:

ratio * k water + (1 – ratio) * k air = 0.037 W/K/m – 50% more than just air

For the best case it would be:

1 / (ratio/k water + (1-ratio)/k air) = 0.0255 W/K/m – virtually the same as just air

For synthetic insulation, the fibers run mostly sideways and not from front to back surface so the best case is probably closer – increase in conductivity due to water is insignificant.

If fleece could absorb the same amount of water, which might be different than Primaloft, it’s fibers actually go more from front to back so it might be closer to the worst case.  Except there are also fibers going parallel to the surfaces and a lot of the insulation of fleece is the air layer on both sides which wouldn’t be affected by the water in the fleece.  Again, I think increase in conductivity due to water is insignificant but it’s less clear.

I’ve looked around but haven’t found anyone that looked at this theoretically or experimentally, just stated without justification or quantity that water in the insulation increases conductivity.

primaloft sandwiched between nylon —> not a baselayer. not against the skin. not wicking. has a lot more air in it because it is a loft layer. if we are talking about loft layers, then we must introduce the effect of moisture on the loft itself (that 0.5″ thickness will flatten when it gets wet).

why choose a material that is not representative of the wicking fabrics at the center of the debate? whatever it is…i’ll play

i have a few fabric samples from a project i did a while ago. wish i still had some 200 power grid, but not about to cut up my favorite fleece hoody. i do have polartec power stretch; similar material/fibers to the other synthetic baselayers, but not as absorbent, so probably a bit under representative of moisture displacement of air.

the test piece is 2013 power stretch — 3 7/8″ x 4″ x 3/32″ — 1.45 cubic in — 23.76 cubic cm

dry weight – 3 g —- wet and shake out until drips stop (nearly soaked, moderate to heavy sweating for me)- 15 g (12 g / 12 cm3 water) —- squeeze as much out as possible (damp, light to mild sweating for me) – 9 g (6 g / 6 cm3 water)

6 cm3 / 23.76 cm3 = 0.2525 ——– 12 cm3 / 23.76 cm3 = .5050

previous poster’s  calculation of ‘water to air/insulation’ for a sample of nylon covered primaloft (a loft layer material) —–> 0.021

My calculation using the exact same parameters, but with power stretch —–> 0.25 – 0.50… 12x – 24x his value

i am the first to admit that power stretch is not the ideal material for the test (though i do have a top and bottom and prefer the power stretch bottom base for most cold weather activities); however, on the low end (0.25 ‘water to air/insulation’), it feels less damp than what i sweat during mild to moderate activity in cold weather. so i am calling this value the reasonable minimum value for this experiment.

one other point to note, for whatever it is worth: i do not sweat uniformly, and cannot remember a time in cold weather i have ever wetted out my whole base layer. i have saturated (beyond the high end of this test) specific spots around my core (arm pits, chest, back, shoulder straps, hip belt/waist/harness areas), though usually the moisture is somewhere between. so wetting an entire base layer…not likely. still dangerous when only a few spots are wet…definitely.

if anyone has a chunk of power grid/dry or cap base they can perform the test on, please do. i will look around to see if i missed anything.

Very good!  and sorry Eric : )

I used Primaloft because that’s what I had, yeah a lot different than a base layer

The 0.5 inch loft did not measurably change when it got wet.  I tried to determine this very carefully.

In base layer material, the ratio of water to total volume is 0.25 or 0.5?  That’s totally different, conduction would be a factor in that case.

One thing that would be counter to that is that the base layer doesn’t provide hardly any insulation because it’s so thin.  Most of the small amount of insulation is provided by the air layers on both sides of it.  This would not be affected by the base layer being wet – no conduction.

Your base layer is 3/32″ = 0.09.  The air layers between skin and base layer, and between base layer and outer layer are probably an inch?  So the total system heat loss from conduction is reduced by a factor of 10.

Okay, maybe conduction is a small effect.

I still think it’s mostly that you just have to evaporate that water which takes a lot of heat, and it doesn’t matter very much where that water is.

Which takes us to something actually useful – if you start sweating, remove insulation or slow up.  Wicking base layer won’t make a significant difference, and maybe will make things worse because you won’t notice when you start to sweat.  I think this is consistent with Inuit experience, don’t they say to be careful not to get wet from sweat?

One thing that would be counter to that is that the base layer doesn’t provide hardly any insulation because it’s so thin.  Most of the small amount of insulation is provided by the air layers on both sides of it.  This would not be affected by the base layer being wet – no conduction.

this discussion is not about insulation, it is about wicking moisture against the skin. and moisture in an insulation piece would absolutely conduct cool towards you and warm away from you. conduction/convection work in series; the effect of conduction does not stop just because the water is a bit farther from your skin.

Your base layer is 3/32″ = 0.09.  The air layers between skin and base layer, and between base layer and outer layer are probably an inch?  So the total system heat loss from conduction is reduced by a factor of 10.

maybe we should define base layer? base layers are intended to be against your skin…mine certainly are, because —> wicking. an inch from your skin? that is not a base layer. my regular t shirts do not even sit that far from my skin. and when you skin and base layer have some moisture, they will stick together.

Okay, maybe conduction is a small effect.

I still think it’s mostly that you just have to evaporate that water which takes a lot of heat, and it doesn’t matter very much where that water is.

you are welcome to your opinion, i will take the science and collective experience on this site and others. but one point of fact: where the water evaporates matters very much in heat loss. the reason evaporation cools your body is because the heat energy that moisture takes as it vaporizes comes from adjacent moisture, reducing the temperature of the moisture around it. when this is against your skin, either directly or in a base layer (against the skin, in case we are still confused on what definition of base layer is being used), the cooling water cools your skin. if the liquid is removed from your skin before it evaporates, either from wiping, dripping, this elusive ‘base layer’ 1″ from your skin, etc… then the cooling effect of vaporization is severely reduced, even eliminated.

Wicking base layer won’t make a significant difference, and maybe will make things worse because you won’t notice when you start to sweat. I think this is consistent with Inuit experience, don’t they say to be careful not to get wet from sweat?

they do make a difference, hence the prevalence of wicking base layers in cold weather activities all over the world; otherwise people would wear super cheap cotton shirts. they are probably scared away by all of the accounts of frostbite from wet cotton against the skin in the cold.

people need a wet shirt to know they are sweating?

the Inuits wore two parkas: one was hide out, the other was hide in, so they had [often caribou] wool against their skin. wool/fur base layer, because they do sweat, and getting it off their skin was a high priority.

There’s an air layer between base layer and outer layer.  There’s a small air layer between base layer and skin even with tight fabric.  Total is maybe 1 inch.  You have to average over the entire body.  My base layer is loose, so there’s extra air space so it’s warmer.  And my outer layer is loose also.

If you’re talking warmth, you really need to look at the total system.  If the base layer provides a negligible portion of total insulation, then it doesn’t matter if it’s reduced because it’s wet.

It seems like this is a bit controversial on this site, some people are skeptical that wicking helps, some people swear by it.  I’m in the skeptical camp, you’re not, that’s okay.

I need a wet shirt to know I’m sweating.

The heat of vaporization is the same regardless of where the water is.  If it’s against my skin, it will be colder there.  If it’s mid way through my clothing, it will get colder there but then it will draw heat from my skin.

If you could wick the liquid water to the outside, and it evaporated there, it would get colder, but maybe wind would bring it back up to ambient temperature?  Except evaporization is very slow at the temperatures we’re talking about, you really need to warm it up from body heat.  An outer jacket does not wick water to it’s outside.

Even if it’s not significantly warmer, I think wicking base layer may be more comfortable, at least based on people’s experiences, so that’s great.  People should use it if they like it.

jared …

ive gotten a base layer totally soaked …. freezing winter rains

jerry … i think i see the misunderstanding …

i think the “misunderstanding” is to assume folks would be using the thinnest base layers (i tend to do so and you as well) … weve seen folks rave over the cap4/t2 as a base (or almost base) layer … i will tell you from personal experience that it will hold a decent amount of moisture, especially in high humidity cold environments where the moisture doesnt evaporate away quickly (one time in the winter we went to the pub after a night snowshoeing in the freezing rain/slush/snow and it didnt dry out enough  even at indoor temps with me wearing it and a softshell, getting chilled while eating a steak!!!)

the other “misunderstanding” is that i think your not looking at it form an “active” vs “inactive” stand point … when i say wet non wicking base layers will cool you down, is that youll soak through your base layers OVERHEATING when active … then when inactive, youll cool down quickly

the wicking is needed so you can transfer large amounts of heat and moisture to the outside when active … if you cant you will overheat and be dehydrated in winter … even with a “minimal” setup you still need enough to prevent frostbite and being soaked from snow contact (often a shell and base at minimum)

remember in winter you will often work HARDER than summer for the same distance gained … with added winter gear, the resistance of snow (especially breaking trail), having showshoes or crampons on your feet, dragging a sled, etc …

while you are correct that one should simply not sweat … the reality is that modern athletes pushing their limits in winter WILL sweat to a certain degree … ive yet to see anyone skin or snowshoe with a 20-30 lb pack a few hundred metres upill and not sweat especially breaking trail …

when folks do sweat the base layer needs to be able to move that sweat away from the skin … as when they stop there will be an instant chill effect … this can be reduced, but not eliminated with a puffy (belay jacket) at stops

its a really simple test … try wearing cotton base layers in the winter for the same very active pursuits and folks will feel colder in the “inactive” (chill) state as the water stays next to the skin, even with a belay poofay

i think you are looking at the garment in ISOLATION and not taking into account how modern layering works in winter … the entire thing works as a SYSTEM and with different METABOLIC rates

from some aussie bum …

http://researchbank.rmit.edu.au/eserv/rmit:7895/Wardiningsih.pdf&gathStatIcon=true

a little quote from MIT school of engineering …

“Wicking fabric will also keep you warmer in winter,” says Christie. Since wicking clothing keeps the skin dry, the body stays warmer because dry skin doesn’t transfer heat to the air as easily. “It’s great to have wicking stuff so you don’t have the cold, wet material sitting on the skin and sucking away all of the heat.”

http://engineering.mit.edu/ask/why-do-we-sweat-more-high-humidity

from those fine folks with guns …

and on winter metabolic expenditure …

http://www.usariem.army.mil/assets/docs/publications/articles/2005/tbmed508.pdf

of course the question does come into mind … does it really matter if one is just walking in mild conditions and groomed trails with light packs?

for that probably anything will work …

;)

Wicking works, but its importance depends on the person, activity, and conditions. I hope there’s at least agreement on that.

In hot weather, a wet cotton T-shirt works, but I find a wicking mesh material like that used by Sierra Designs in their solar shirts to work better (90D 94% Nylon / 6% Spandex, Wicking, UPF 35). The SD fabric dries faster, and I believe that some of that is due to the more open weave of the material compared to the typical cotton T. Evaporative cooling simply works better when air can move through the fabric, and a soaking wet cotton T stuck against skin doesn’t allow much air to move through it. I don’t care to wear a sweat saturated shirt for hours, and there’s not much reason to do so with so many other options.

In cold weather, having damp or wet clothing is going to happen with any real exertion, just as Eric said. In my experience, the key is finding the right clothing system that dries as quickly as possible when conditions allow. One of the most difficult challenges faced by early polar explorers was overcoming their moisture saturated gear, as it constantly froze into icy armor even as they wore it, and their sleeping bags were often frozen into rigid tubes of misery. I’m sure Cherry would’ve given all of his shattered teeth for a full kit of modern, wicking gear.

Awesome links! There are some good ones on heat stress too.

(at the bottom of this page)

Just as an aside:

In Japan we have a brand called Finetrack, started by people that used to work at Montbell.

They have some really great wicking pieces to deal with the super hot humid context, and with the hellacious rain situation. They also make almost all their pieces with ventilation zippers, so in their fleece, in the soft or wind shell, and in their rain shells – so you can ventilate right down to your base layers.

They don’t have an international site, but for the interested here are their wicking layers.

http://www.finetrack.com/product/skinmesh.html

http://www.finetrack.com/product/powermesh.html

If you see people at the longer races, or self supported races crossing Japan through the Alps, most people swear by the Powermesh or Skinmesh layers.

Should I speak up against “vents” in clothing?  Too small area to do any good?  Just marketing spin?  No, better not : )

Jerry, I’m not a fan of the pit-zip-marketing-checkoff, either.

While I agree that a thick layer of marketing hype usually accompanies much of what we see, there may still be some concrete value under the ad copy. “Vents” in clothing may be of little real value, or they may be useful if they’re designed into the overall way the garment ventilates. In my experience, better ventilation is more important than whatever magical claims are made about a garment’s breathable membrane. There aren’t that many ways to remove moisture from a clothing system, and wicking fabrics combined with effective ventilation seem to work pretty well. Even when the wicking/membrane/ventilation combo is overwhelmed, the clothing can dry out fairly fast once conditions improve.

I think WOOL is the closest thing we have to what nature intended for “clothing” and it works for me.  I dislike synthetics in general; while it may be more “wicking” in the lab, I think it also makes me sweat more in the first place. I wear my merino pieces year-round, from tank tops to heavyweight baselayers, and everything in between. I have merino underwear, too.  Wouldn’t wear anything else on my feet.  More comfortable, better at temperature regulation, doesn’t smell, never takes on that slimy-tacky-dirty texture.