Applying 25 years of experience preparing outdoorsman with apparel to combat diverse weather conditions, David Kramer shares how layering systems can hike up comfort levels during your activity of choice.
After 25 years outfitting people for everything from Colorado ski trips to backpacking on the Appalachian Trail, I want to share how to dress for adverse weather and varying levels of physical exertion. Addressing these issues ensure ultimate enjoyment (and comfort) regardless of your activity.
We’ll begin by reviewing the 4 ways our bodies lose heat. Later, I’ll share which pieces of clothing will keep you most comfortable based on your particular activity or conditions. Finally, we’ll walk through an example scenario you could find yourself in so you’ll know how to best apply layering systems for your specific needs.
If you take my insight and apply it during your next outdoor excursion, I promise you’ll find your time in the field more enjoyable and will be surprised by how much versatility layering systems offer.
Good Layering Systems Give You Flexibility a Single Jacket Does Not
From braving bone chilling cold as fleeting ducks flutter overhead, to escaping the sting of a wind driven drizzle, you’re sure to get elemental refuge from layering systems. There’s no doubt about that. But to select the appropriate layers for your outdoor application you must understand how you lose heat and how exertion and terrain intersect heat loss.
Our Bodies Lose Heat in 4 Ways
1. We Sweat — Evaporative Heat Loss
Water on the skin. Whether from a shower, sweat, or rain, water pulls heat off the body 27 times faster than air does. This is how evaporative heat loss works.
2. We Sit on Cold Bleachers — Conductive Heat Loss
Sit in a cold tree stand and your rump goes numb. This is heat conduction in action.
3. We Glow Under FLIR — We Radiate Heat
If you don’t have a warm enough jacket on, you “bleed off” heat via radiant heat loss.
4. We Get Chilled on Windy Days — Convective Heat Loss
Wind chill magnifies cold exponentially. The more blustery the day, the more raw you feel. This is convective heat loss.
Taken individually, these 4 ways of heat loss are fairly simple to deal with. They’re compounded when 2, 3, or 4, happen at once. Facing multiple forms of heat loss simultaneously builds a strong case for a solid layering system.
Here’s An Example
Imagine a morning with temperatures hovering around freezing. We’ve all been there. You put on a warm fleece before hitting the trail head. Fleece is the play here, because as your body radiates heat, the fleece captures that warmth.
Next, you sling a pack on your back and stomp up the trail. After twenty minutes, a swell of sweat surges in route to the ridge top. Sweating is your body’s natural way of cooling you by evaporating moisture & heat.
Now, thirty minutes into the hike you’re boiling and pouring sweat, so you stop to shed the fleece. As soon as you drop your pack and fleece, you’re quick to chill down to a shiver. Once you put the backpack on and start walking again, you begin to get warm.
The last 5 minutes of the hike, (prior to earning a beautiful view), you’re sheered by swirling summit winds. The wind soothes at first as it cools you off a bit and your hard work is rewarded with a great view. You take the pack off, plop down on a rock.
Time for some rest.
That is, until about 3 minutes later when you’re shivering again. Your cotton “Captain America” shirt is soaked and you realize the extra bit of money you should have spent on one of those fancy quick dry shirts was a missed opportunity.
Now you’re wet, sitting on a cold rock, in the wind radiating heat — all 4 heat loss methods are in full swing.
Welcome to How Layering Systems Hike Up Comfort Levels
Ever put your coffee in an insulated travel mug? This fancy mug slows the transfer of heat considerably so thirty minutes into your drive, your coffee is still hot. The same thing happens when you pour ice water in your mug — it slows the ice melting and water warming.
How does your mug know whether to warm or cool?
Insulation works on a warm (or cold) beverage the same as a piece of fleece or a puffy jacket does for your body — it slows radiant heat loss.
Your body has a temperature regulation system more advanced than any sky scraper in any city. When you don’t have enough insulation on, it draws blood away from your extremities where it tries to maintain core body temperatures of vital organs.
Conversely, when you start to overheat, it produces moisture to cool your body down. When we sweat, we are trying to cool down — usually because we are exerting ourselves. The challenge comes when we’re sweat laden, and we stop exerting. This is where items that maintain some amount of warmth when wet are important.
(See Captain America shirt reference above).
A Merino or Synthetic Shirt is Probably the Best “Warm When Wet” Solution There is
When you step out of a steaming hot shower, into your fogged-up bathroom, you have a chill on your body. As soon as you wrap a towel around you, get the moisture off your skin, and you’re back sitting in a steam filled bathroom you become hot again.
Why? Well, that [water on your skin cools you 27 times faster than air does].
Having Clothes that Wick Moisture Away from your Skin, to where you Can’t Feel It (and Hence Don’t Chill Off Too Fast) is the Goal of All Good Base Layers Out There
If you’ve ever been to a winter football game without your padded bleacher seat, well, that’s a mistake you’ll never make again.
Sitting on cold cement or metal for hours is no fun. Sleeping pad manufactures sell us on luxury, but the most basic function of that any self inflating air mattress is to keep you from becoming hypothermic.
Same goes for folks who take a precision shooting course — shivering doesn’t help bang steel at 800 meters. Laying on frozen ground becomes comfortable by a shooter’s mat and a pair of long johns.
As a Layering System, a Good Base Layer, Combined with a Mid-Weight Fleece, and a Synthetic Puffy Jacket, is the Best Set Up for Near Freezing Temperatures (While Static or at Low Exertion).
If you pick up a ruck and start hiking, you’ll immediately shed the puffy, and probably take off the fleece too (unless you are like my wife, with the circulation of a cinder block).
Start off cold and you’ll be happy 10 minutes into the hike. But it’s good to have the puffy at the very top of your pack so when you take a break, you can pull the puffy on to preserve the warmth (stopping radiant heat loss).
A Good Base Layer Will be Warm When Laden with Sweat, and After a 10 Minute Break Will be Nearly Dry
The fleece you buy, or even the Old Navy one you got at Goodwill for fifty cents is made of polyester. Polyester absorbs .005% of it’s weight in moisture which is what made it so good for the disco floor in 1978. When you were done looking fabulous on the dance floor you were dry and cool asking that Farah Fawcett looking gal what sign she was.
Use the findings here and apply them during your next outdoor excursion to amplify your level of comfort.
In our next lesson we’ll cover the intersection of being comfortable and looking good — like a bad-ass hippie ninja from seal team ranger rescue recon.
What’s Your Take on Layering Systems? Have Anything You’d Like to Share? Let Me Know Which Apparel Selections Work Best During Your Favorite Activity.
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