I wear UA cold gear under the usual cargo pants & fleece shirt, or expedition weight fleece undies if below 20F. The USGI waffle type undies are good as well. I prefer synthetic or merino wool; cotton kills in cold water. I avoid cotton and jeans in winter. Lightweight Arcteryx Leaf Atom SV hoodie, or Browning parka if really COLD. Gore-tex goes on over that if rainy. I NEVER get cold. Just my hands sometimes, but I got me some ragg wool fingerless gloves I wear over full waterproof SealSkinz gloves, so that problem is fixed. HTH!