Originally Posted by Bob Ross

I haven't read any of the responses so I apologize if I'm repeating what's (hopefully) already been said. You'll do better with a base layer. You want to separate the moisture-transport functions from the insulating functions in your winter apparel. A good base layer will move the sweat away from your skin so that you don't get chilled. The air space between that base layer and your outer layer -- or, in colder weather when you're using a 3-layer system, the insulating layer between that base layer and your outer layer -- provide the warmth. A thermal jersey makes an excellent insulating layer, but doesn't do as well for moisture transport.

Originally Posted by Tesgin

Wow. This is an excellent thread. Extremely helpful. It has prompted me to do two things: one is that I did order a PI Select Thermal Jersey, but I also added a Craft Pro Zero sleeveless base layer. I am excited to see how I do. I will post a f/up to let you know.

Again, thank you all for your input here. I've learned a ton.
Tesgin