I got my old Army issued polypropylene long underwear and the more recently issued silk weight long underwear. Neither of them are super warm, but that’s kind of nice once I start working hard and gotta shed some outer layers. The silk weight stuff is like UnderArmour, it’s moisture wicking, very durable, doesn’t seem to show wear and tear no matter how many times it goes through the washer and dryer. Both of them get stinky by the end of the day. Like noticeably more so than cotton underwear and t-shirts. Such was always my experience with real Under Armor too. Like I can wear it and not even work that hard and I’ll have this amplified body odor within 10 hours or so. That’s a dealbreaker, I’m self conscious about hygiene and I’m a hugger. Often a huggie too I suppose, but I reciprocate, so I cannot be stinking. Methinks the answer is wool of some type. Thin smart wool or thin merino base for under 40F but above maybe 20F, then same material but thicker or a doubled layer of it for below 20F. I’ll know better once I buy some and wear it in the cold.
Until 3 years or so ago, I’d never tried Merino wool socks. I thought I was fine w the usual Hanes or Fruit of the Loom white athletic socks, and the prices scared me, I’m a bit of a frugal bastard, plus I thought they were delicate and easy to ruin in the washer and dryer. I was so wrong and should’ve bought some decades ago. They’re so comfy, even in warmer weather, if my feet get wet, they don’t feel as wet as cotton, they’re fine to wash and dry with all my normal clothes, and they almost seem to prevent foot odor. I was so impressed, that I buy merino wool socks as Christmas gifts for anyone on my list that I think needs them and just doesn’t know it yet. So a base layer made out of that stuff, sounds kickass to me.
As I get older, the cold bothers me more and more, especially hands and feet.