Fishnet base layers. They work, and you want them.

[THLR]

Here's where fishnets are stellar. Temps drop towards -10°C in the morning, significantly warmer in the sun but well below freezing.

I'm wearing woolnet x2, a wicking layer and windbreaker. Note how I don't need my puffy for glassing as I'm basically dry

 

[isleofGough]

Still, down or synthetic down are needed if you are standing still in sub zero temps.

 

[fwafwow]

I'm wearing woolnet x2, a wicking layer and windbreaker. Note how I don't need my puffy for glassing as I'm basically dry

Sorry for perhaps a dumb question (one of my specialties), but do you mean you are wearing two layers of Woolnet?

 

[THLR]

Not at all. Yes! I wear a woolnet tshirt, a thin woolmesh crewneck (smaller holes) and on top a hoodie; this one made for winter trail running

 

[fwafwow]

Not at all. Yes! I wear a woolnet tshirt, a thin woolmesh crewneck (smaller holes) and on top a hoodie; this one made for winter trail running

Thanks. I will research tomorrow to find the t-shirt. I currently only run/rock (have to use powerful verbs with these mesh pieces) the Aclima Woolnet Crewneck (which is long sleeve), so a woolnet t-shirt would be a good option to wear separate, or in addition.

 

[Dobermann]

Thanks. I will research tomorrow to find the t-shirt. I currently only run/rock (have to use powerful verbs with these mesh pieces) the Aclima Woolnet Crewneck (which is long sleeve), so a woolnet t-shirt would be a good option to wear separate, or in addition.

Here's the Aclima one at Varuste: https://varuste.net/en/p80210/aclima-woolnet-t-shirt-mens

Not many sizes in stock, but they seem to re-stock often.

And not sure if that's the one that @THLR uses, or another manufacturer ...