Cheap sweatsuit as VBL

I think it could work as wind/rain protection as long you keep moving.  I do that sometimes – intentionally under-dress and keep moving in the rain.  e.g. nylon shorts and PP t-shirt but then modulate my hiking speed to keep warm enough.

I do feel more nervous about pushing the envelope like that – I’ve got to be really attuned to any hypothermia because vigorous activity will suppress shivering.  And I get really nervous if I don’t have the back-up clothes along to put on immediately, if, say, the wind increases and I not staying warm enough or I twist an ankle and can’t maintain the exertion.

But it seems like it could work as a way to keep most of your clothing dry.  Wear the sweatsuit till you’re done hiking fast, maybe use a micro-fiber towel to wipe yourself down of sweat, and then put on dry clothes on once you’ve arrived and set up your shelter.

I’ve seen people out jogging in them and once gave a guy a ride home after he’d locked his keys in his car.  I was impressed how completely waterproof they are and how much sweat one generates per hour if you contain it all in one place.

Interesting that you mention wiping with a micro-towel and putting on dry clothes; I was thinking more of just adding a insulating layer on top for camp chores like a puffy down top and bottom and keep both the VBL and the puffy clothing in the sleeping bag. To me that would be the ultimate winter UL system, it would be pretty much impossible to get cold in a perfect (read: perflectly impermeable) VBL (and bonus heat if it also has a reflective coating inside). You would get sweaty and feel clammy (or even fully wet) but that sweat wouldn’t hurt your insulation as you would be wearing none while hiking. To dump your sweat pool accumulating you could simply pull on the elastic ankle cuffs for the water to flow out. If you wore no base layer under, there would never be too much water sitting on the skin (a polypropylene base layer would also be good at not holding water and stoping the clammy feeling; maybe polyester too but it holds much more water than polypropylene). In the sleeping bag you would still heavily sweat in your VBL but that moisture would not end up in the insulation and you would only have to dump your sweat outside your tent in the morning. I’ve read Andrew Skurka article on VBL (https://andrewskurka.com/vapor-barrier-liners-theory-application/) and I’m super impressed and would like to try.

Does VBL really work if you are moving? My experience

a) riding my bicycle with my high-vis jacket and no sleeves, eventually the wetness of my skin against the jacket is disgusting, uncomfortable

b) wearing my EE copperfield windshirt and pants in my sleeping bag, my body might get a little moist but it’s not uncomfortable because I’m not overheated

It surely is very uncomfortable, no doubt. But it think it’s because we are used to be dry 24/7 except when swimming or taking a shower/bath. I wouldn’t mind to be wet and uncomfortable when hiking. This water would be hot, I feel the real problem is when that water is cold (rain or falling into cold water). But I’m probably wrong. Next time I’m at Walmart I’ll buy a cheap sauna suit. I’m only concerned about the health hazards of PVC, PEVA would be much better.

Long-term VB use can put you at risk of various forms of jungle rot.  I’ve got a spot between two toes on my left foot that I’ve learned goes to athlete’s foot if I spend two days crossing numerous rivers without letting my feet and socks dry out.  Putting a dab of topical anti-fungal cream there in advance avoids any problems, but I have to remember to do it in advance or take it along.

Of course, the fungal infection has to be introduced somehow – some are just in the air around us, while others have a clear source.  I remember EMT / Paramedic friends chatting in the 1980s, comparing rashes they each got after a particular patient, and comparing their logbooks to figure out which Vietnam vet they’d both treated.

David, I was under the impression that jungle rot and other infections happen because of the fabric that holds  water in its fibbers become a breeding ground. But without any fiber in a VBL (without a base layer under it) there would be no matrix on which the bacterias or fungus would grow. Yes there would be some micro-organisms under the VBL, but without the fiber there would be much less space for them to grow. Also, the sweat wouldn’t stay stagnant at the same spot and thus wouldn’t allow bacterias and fungus to consume it (it takes time), it would keep on flowing and pool, and then you could dump it out of the suit (with whatever microorganisms inside that water). Bonus, I know that some PVC or PEVA are anti-mildew (my shower curtain is sold as being « superior anti-mildew protection »), probably other materials too

Emile, I wasn’t thinking of the VB materials, but of your body underneath – a few days of moist skin that never dries out and problems can develop.

Fungal growth on gear is absolutely a problem but one I’ve avoided when I’m consistent about airing out a tent or tarp or parka as soon as I get home, inverting it a few times in the process.  It’s perhaps my biggest hesitation in loaning gear.  And while on the hike, for weight reasons if nothing else, if you’ve got wet clothes or rain fly, drape it over your pack as you hike or over a bush during lunch to dry it out.