But bicycle clothing and accessory makers are quite happy to sell you specialized gear for winter riding, most of which is quite advanced and effective. Wear a helmet. Torso Wear an undershirt. Despite the lack of arm coverage, a sleeveless vest retains body heat nicely. Schlepping papers, clothes, a box lunch, and other gear can be a problem.
Backpacks work well, though they lack an executive look.
The extremities are where you really feel the cold. It's an almost miraculously cozy combination. It's perfectly possible to cycle in long underwear and civilian pants. Most cyclists opt for mountain bikes, while a small but vocal faction rides thin-tired road bikes through the winter without mishap. Expect water to accumulate inside on very wet rides.