Key paragraph:
> The data proves that the gear of the past is capable, but it has a narrower operating window. If you stop moving in Mallory’s kit at 8,000 meters, you will freeze quickly. Modern gear buys you a safety margin if you become static.
> The data proves that the gear of the past is capable, but it has a narrower operating window. If you stop moving in Mallory’s kit at 8,000 meters, you will freeze quickly. Modern gear buys you a safety margin if you become static.
Traditional materials still have a place though. Material science has not beaten down feathers or wool yet, for the most part.
It's a way to shed water: Wearing waterproof, non-breathable layers often is worse than not, because the moisture your body releases and that gets trapped soaks you from the inside as surely and rapidly as the rain. (Maybe it's a bit warmer.)
While dry, or intermittently wettened (so it can still shed water). Numerous independent tests show that it doesn't breathe at all, once the surface is fully wet. Also, Gore-Tex is no longer best-in-class amongst rain-shedding breathable fabrics; it simply has name recognition.
To be fair, few things do breathe once their surface wets... but wool's surface is so convoluted by the twisty, hydrophobic threads that it rarely gets fully wet on the surface.