Excellent article. Years ago, at an AMC NH winter backpacking course, we were taught that it is possible to dry base layers by simply hiking in them. So even if your base layers become damp from sweat (or whatever) during heavy exertion, you can dry them by simply donning an extra synthetic insulation layer an hour or so before you plan to arrive at your camping destination for the night. Hike slower than you normally would for that last hour, you want to be warm but not sweating. Everything will be dry by the time you get into camp. Sounds exactly like the advice given in this article.
For several years after receiving that advice, I still carried an extra base layer with me on all of my trips, "just in case," but I employed that technique to great success. In the 15 or so years since that course, I've never once needed the extra base layer since I've always been able to dry the ones I'm wearing, even after sweating pretty heavily on several occasions. Five or so years ago I stopped carrying the extra set of base layers. And I'm not dead yet.
Funny thing is, I've always assumed total submersion to be the one situation where I might NEED an extra base layer. But this article suggests that's not so. I believe it. Of course I'm not a Navy SEAL, and later in life I may not have the option to push my body physically through a challenge like this. But for now it works for me.
One other thing the article doesn't stress enough is that eating when you're really cold is really, really hard. It's the thing you absolutely need to do, but in a twist that would seem to be at odds with evolutionary theory, most people (myself included) have absolutely no appetite when really cold. On a few occasions I've had to absolutely force myself to chew and swallow a few squares of chocolate just to get the furnace running again. Strangely enough, once that initial burst of metabolic heat hits, I'm suddenly ravenous! I've seen this exact sequence of events unfold with others on several occasions.
