As the warmest fleece in Patagonias line, the Mens R4 Fleece Jacket makes a great choice when you want to get out on the coldest winter days. The Polartec WindBloc laminate keeps the wind from sucking away all your heat, and Patagonias high-loft design ensures you get all the warmth you want. This well thought-out jacket also features seamless shoulders, so you dont get pressure points when wearing a backpack.