Body Protection

Dress for maximum visibility. Bright coloured garments accented with highly reflective tape are ideal. There are also a variety of personal flashing red LED lights that mount quickly and easily to the back of your helmet to add extra security.

For truly foul weather, well-layered clothing is the easiest way to regulate body temperature and stay dry. Even though it may be very cold outside you will perspire if you are riding hard, so try not to overdress.

1。A thin moisture-wicking layer against the skin moves perspiration away from your skin and keeps you dry.

2。Above your wicking layer, an insulating breathable layer like a midweight or heavyweight fleece is ideal.

3。As an outer layer we recommend a wind-deterrent jacket or shell. Some people even use old ski jackets! You'll probably also want shell pants. Warning: Your outer layers, attacked by road salt and slush, may get wrecked.

for even colder temp, I think heatgear or coldgear from underarmor wore as under garment will do the work;outside you need your normal winter clothes.
I think underarmor coldgear or heatgear is for undergarment only. I have a underarmor base 2.0 it is warm. HH(henly hensey) and columbia are all other good choices( I wore all of these so I knows they are good too)