When I board I rock my longjohn shirt, a regular tshirt, and than my 686 X3 two nine jacket. You can read what my jacket is made of, if you go to products, than on the top row, second image.

Even in the single digits I usually where a long john and a shirt. I usually where my back pack, which has a sweater, and other shit. Only time I get cold with that on is when I am on the chair lift, once I strap in and get going a 100ft or so I am warm again.