Best Cold weather clothing I have is a Thermal base layer. In fact I have two base layers that I use. For summer use it is just like a string vest but wicks away moisture with any Summer long or short sleeve jersey. Without the "String Vest" Moisture does not wick away as quick and I can get cool and damp whenever I stop. The Thermal one though is brilliant. Keeps me warm and dry at any time of the year. Including the summer rides when the temp does not get above 60. (Which I had plenty of last year)