Webfoot wrote: ↑September 18th, 2018, 3:41 pm
Lurch, thank you for your advice. I have a follow-up questions I hope you will entertain.
I'm all for Q&A Time, I'm not the end all source by any means, just been doing and teaching this awhile and seen lots of things, good and bad!
Webfoot wrote: ↑September 18th, 2018, 3:41 pm
You emphasize "STAY DRY." What if wet layers are contained under a shell? I know one does not want to soak down, but wet fleece under a wind shirt still feels warm. When more prepared I have both a wind shirt and and actual shell with me; my plan is to put the wind shirt over existing clothing,
even if wet, then any extra layers I have (e.g. down puffy), then my shell. Is this a good plan?
Like just about everything out there, the answer is some form of
it depends, or
sometimes. It's really dependent on your scenario, and most of the stuff I laid out above would be for someone who is attempting to bed down, or can't move, and is no longer up and being active. In most modern (non-cotton) fabrics, and some oldschool, wools and such, generally speaking the more hydrophobic the individual fibers are the better it's going to perform while wet. The easier it will be to dry, and wring out excess water. You definitely do retain insulative properties in wet clothing, how effective that will be is impacted by a whole host of things. Wet clothing under a shell will still keep you warmer than nothing, but you're essentially hotboxing that moisture into the system, You're potentially the only heat generator out there, and at
some point, your energy is going to go into warming that water. Good shells that cut down on external radiation heat loss, remove the convection elements from the outside environment and hopefully help reduce conduction through the ground will go a long ways in keeping that heat close to you. There are oldschool techniques for basically sitting over a survival candle with a poncho. A thermal blanket and a tea candle can make a surprisingly warm sitting shelter.
<Insert Obvious note of caution on bringing flame inside your 'shelter'... especially while wearing flammable/melty synthetic clothing.>
Believe me, I know that
NO raingear will keep you dry in PNW storms if you want/need to be outdoors. The trick is learning to mitigate that,
especially if you know that you don't have redundancy in equipment. Understand what you're doing, what you'll need to be able to do later, and what you
might have to do if SHTF. For example, I wouldn't go wading through a knee deep stream, and allow my boots to get soaked if I didn't
have to for some reason. You're going to soak your socks, probably pants to some degree, saturate your boots in a way that will be practically impossible to field dry, perpetually wet feet is going to lead to all sorts of other issues, and it's just going to make for a bad day.
Layering like you indicated up there is the best plan in cold weather, and doing so in a way that you can, with minimal burden, change out those mid-layers to match your activity level will help. Generally speaking you should be chilly when you start. Usually stop 15 min in for a break and give time to adjust layers before you get too sweaty, since that will probably be your 'working temp' for most of the day. If you stop there-after, you should layer up while stopped, and remove it when you go to move again. I still try and keep a base layer backup for the end of the day that I can change into, even if everything else is soaked and wrung out, having a dry base layer, at least for a little bit is comforting at the very least, and the mental side is just as critical!
Webfoot wrote: ↑September 18th, 2018, 3:41 pm
I'll probably stop carrying the mylar "space blanket" given your opinion of its usefulness. Do I replace it with something? Do I leave out something to make room for a
12 ounce Space All-Weather Blanket?
Personally, I would. I'm not a trail
runner though, and I understand some peoples needs/wants are different. The multi-use side of a legit emergency blanket is undeniable though, and very helpful. If you're packing a water bladder you can always just slide it in the sleeve with it, or even wrap the bladder with the blanket if you want to help maintain it's temp a bit. With any even small backpack they aren't that much of a burden, and I usually keep my folded on the bottom of my pack both to give me quick access through the bottom zip, and also give some additional waterproofing if my pack gets set down on wet ground.
Webfoot wrote: ↑September 18th, 2018, 3:41 pm
Am I right to give shell pants a higher priority than one of these blankets?
Again, I think that kind of depends on the scenario. You would most likely make due just fine with shell pants, and they'd definitely be superior if you were mobile, but many of them are designed to shed heat in an effort to mitigate sweat buildup, not retain it. If it were a hunker down scenario, or if you didn't have an appropriate midlayer to deal with the inevitable moisture buildup under non-breathable clothing, you may prefer the other. Also, remember clothing kind of compartmentalizes your heat. For your torso that's a great thing, and what keeps you alive. For your extremities, blood flow gets restricted to your skin as hypothermia progresses in an effort to retain heat in the core and let your skin/fat act as an insulating layer. Side note: This constriction ramps up your blood pressure. It's why you commonly need to pee when you go swimming in cold water, as your body tries to rid itself of excess fluids to maintain a reasonable blood pressure. It's also at least part of the cold weather thirst suppression reflex, that makes you more prone to dehydration during cold weather. As your extremities cool, you'll loose fine motor control and dexterity, and develop the 'umbles' (fumbles, mumbles, grumbles, stumbles, etc).. If you're still mobile at that point, it can be very akin to being drunk, decision making is compromised, as is your simple ability to just walk around without falling. The bonus of heat generation through movement may be detrimental in the long run with the additional risk posed by 'drunkenly' wandering the wilderness.
In late/extreme stage hypothermia you start to get into the weird stuff. The vasoconstriction that to this point kept your warm blood in your core, ultimately gives out and relaxes, releasing that warm blood to your skin. The huge temperature differential makes you feel HOT, and your loopy drunken state does what any drunken state would want to do, strip off clothing to cool down. There's also a phenomenon called 'terminal burrowing' or 'hide and die' that pushes a very primal urge to burrow into the smallest little hole you can find, making it
extremely difficult to find someone who was mobile to that point if that particular urge kicks in. There hasn't been a whole lot of study on *why* that one exists, but it's most likely some vestige of hibernating mammals. Those two final stage hypothermia traits have lead to all sorts of weird investigations after urban hypothermia cases were mistook for assaults.
And now I'm rambling again so I'll leave it there!