-
It's acting as a vapour barrier - popular in the world of winter climbing etc but doesn't seem to have caught on in the world of cycling (except on this thread)
https://andrewskurka.com/vapor-barrier-liners-theory-application/
I know the soft-shell base layer supposedly breathes but it is much less breathable than normal jersey material. I tried it out for these purposes but I sweat too much even when I'm not working particularly hard. I won't talk about my experiment with vapour barrier socks which was gross
I think genius. And then I try to take the thing off.