Reynolds Oven Bags can be used as vapor barrier socks for cold winter hiking. They prevent foot perspiration from degrading the insulation inside your boots and freezing overnight when winter camping. This is especially valuable if your insulated boots do not have removable liners.
Vapor Barrier Clothing
If you’re not familiar with Vapor Barrier clothing, the basic idea is this:
Wrap your feet, hands, or torso in an impermeable membrane like plastic. The plastic barrier prevents the transmission of moisture from your base layer clothing into your higher insulation layers. This maintains its insulation value longer and is especially valuable over the course of multiple days because you don’t have to dry your layers at night to prevent them from freezing. It also means you’ll stay warmer during the day because your clothing’s insulation value is not degraded by sweat.
The use of vapor barrier clothing can be hard to get your head around because it flies in the face of everything you’ve ever been told about layering and breathable clothing. While you will still want to dress in layers to help regulate your warmth level, they’re not needed to transport moisture from your inner layers to your outer layers anymore. In fact, vapor barrier clothing works because it’s not breathable at all.
Cold Temperature Use Only
Vapor barrier clothing and liners work best in very cold temperatures, starting at about 10 degrees Fahrenheit or less. Much warmer than that and you’ll sweat too much, which gets uncomfortable. This is why vapor barrier clothing hasn’t gone mainstream and is mainly used by mountaineers and other cold-weather adventure athletes that need to minimize gear weight on multi-day trips.
When I need a vapor barrier sock, I wear an oven bag over a liner sock when using a double-layer insulated boot and under a regular hiking sock when using a single layer boot without a removable liner. Whichever boot type you use, you want to make sure the top of the oven bag is closed around your calf so that all of the water vapor produced by your feet stays in the bag and doesn’t leak into your boot’s insulation and dampen it. It’s not as uncomfortable as it sounds and you’ll appreciate dry boots at the end of the day.
Types of Vapor Barrier Clothing
I’ve tried vapor barrier clothing from a number of manufacturers including Rab and Stephenson’s Warmlite. RBH Designs also makes a full range of vapor clothing including hats, gloves, jackets, vests, and pants.
When purchasing vapor barrier socks, you have to worry about how they’ll affect the fit of your footwear. That’s not an issue if you use Reynolds Oven Bags, because they are so thin. Just make sure you get the large sized Reynolds Oven Bags and not the Turkey-Sized ones. Those are too big, even if they can be used as ultralight stuff sacks.
Disclosure: The author purchased all of the products mentioned in this article with his own funds.Editor's note: If you’re thinking about buying gear that we’ve reviewed or recommend on SectionHiker, you can help support us in the process. Just click on any of the seller links above, and if you make a purchase, we may (but not always) receive a small percentage of the transaction. The cost of the product is the same to you but this helps us continue to test and write unsponsored and independent gear reviews, beginner FAQs, and free hiking guides. Thanks and we appreciate your support!