From "The Outward Bound Staying Warm in the Outdoors Handbook" by Glenn Randall.


Page 14

... " When I first bought a VB shirt I put it on next to my skin, added one thin layer on top and went for a bike ride on a windy, 40 degree day. To my astonishment, I was simply too hot. For active sports, I'd recommend VB clothing only for temperatures below freezing. It really comes into its own on days when unprotected water bottles freeze solid before noon - days when the high might be zero and the low 20 or 30 below. For inactive sports, some people recommend its use in temperatures below 65. Personally, I do quite well with conventional clothing down into the 20's, even when I'm inactive. ..."

On page 16 he discusses:
Vapor Barrier Sleeping Bag Liners

He states that VB liners let most people sleep comfortably in temps 10 to 15 degrees colder than they could tolerate in just the bag. A VB liner is particularly useful with down to keep loft loss from happening when the down gets wet from perspiration. He usually leaves his VB liner open at the neck to allow some moisture to escape from the clothes. And on a long trip, take every opportunity to dry your sleeping bag.

In his discussion on socks, he discusses Hyperhidrosis or excessive sweating of the hands and feet and these people find that their feet get so wet so quickly that VB socks do more harm than good. About 10% of folks have this.

If you are a naturally sweaty guy, this may not be your cup of tea, or bowl of sweat.

Be sure to read the good stuff on VB which balances fantastic claims with some realism.

Unlike some Hanger Bangers who excessively trumpet the wonders of their hangup, you need balance in the discussion of something like VB. Otherwise you can end up miserable.