Re Wool. Listening to a program from our Maine PBS station I learned there is a Maine farm which strives to keep alive endangered species of domestic animals : pigs, horses, goats, sheep etc. and in process learned that the wool industry is depressed because people are not buying many wool garments.
Perhaps many folks, like myself, associated wool with the itchies ... but that is no more!
Last winter I bought a light weight wool Merino outfit -- slacks and a top (Nordstrom catalogue if I recall correctly, either that or Bloomingdale's brochure.)
In a washable wool!
It was so good, and comfy, I ordered another set in a different color.

I had been wearing heavy weight fleece "sweats" and was still cold. Swapped for the wool outfit and Voila!
Warm, no itching, comfortable, looks good, feels soft.
And, I could turn the heat down.
And it sure is more flattering than bulky old fleece stuff.

All in all it beat all the synthetics I own by a country mile. More wool for me this coming winter!

Re silk:
heavier weight is warm in winter - I used to wear silk underwear (long Johns type ) for winter sports.
And it's lighter weights are cool in summer. Some silk is diaphanous and floats around you like a rainbow cloud. Wheeeeee.
And now I find if I ever get shot by Cupid's arrow I can just pull the fabric and get rid of the pesky imp.
Good news. Thanks Helen!!