Originally Posted by dejoha
............While not the ideal temperature conditions, the effect was immediate and welcome. I slept in this makeshift VBL all night and slept warm and comfortable. Since the VBL wasn't completely sealed, I had some moderate ventilation, but this "burrito" style really helped my body regulate its temperature until my metabolism kicked in.
In the morning, I pulled off my top quilt and my legs were still warm and cozy inside my tarp wrap. Pulling the tarp away, my legs immediately felt cool. It was amazing.
Typically, VBLs are recommended only in very cold and dry conditions. I wanted to share this experience because it gave me a sort of "last resort" method for staying warm in unusual circumstances.
Raisins bump of this thread helped me realize I missed your excellent report from last July, Dejoha. It is great to see this example of a VB saving you at least from an uncomfortable night in conditions that most would consider miserable for a VB, only in the 40s! That is NOT traditional VB weather, yet it saved your bacon, so to speak!
And you illustrated another point: only in the 40s, and due to being debilitated from a rough day, with a no doubt high quality 40F TQ plus all your clothing, you were close to shivering! Which probably would have only got worse during the night. That makes a point none of us should miss! May I ask, what was your UQ?
I bet you had some major evaporative cooling(EC) going on, even if temps were not very cold. VB to the rescue! Stops EC instantly! I'm betting that even if you had some minor condensation or clamminess, you still would have been warm. Better clammy than cold. Even if you outright sweat, better your thin base layers are damp than freezing from EC, plus that vapor is condensing or sweat soaking into your down night after night. The sudden evaporation of that moisture is what you felt when you finally took the tarp off, EC!
I see that 21% have used VBs successfully, much more than I would have predicted. I see that 73% have either never looked into them or are skeptical that they work at all. And 5% have used them and their clothes/insulation got really wet, which I assume was a negative experience. One which I have never experienced. I have been an advocate of VBs sense the 80s, when I got my 1st pair of Patagonia VB socks. For me, VBs have only served to keep my insulation dry as a bone, if you don't count the thinnest possible layer closest to my skin.
Over the years I have used VBs in various forms- mainly socks, but also glove inserts and most frequently space blankets in HH Super Shelters and in the bottom of a PeaPod. I plan to keep on using them, plus a VB shirt I have from Stephenson's Warmlite, and I hope to get some VB pants from them. I know you are supposed to be able to use your WPB rain gear as a VB, but I have a hard time seeing how it could work to full effect. Sense if I sit around in a true VB I tend to feel clammy as the humidity level at my skin reaches 100%. I never feel that in any of my WPB rain gear, so at least some vapor must be getting through.
Thanks for that informative real life report!