The Rule of 20
New runners often dress too warmly on their first cold day out and overheat about 10 minutes into their run, Pappalardo says. "To avoid the problem, always dress as if the weather were 20° warmer than it actually is."
How to Layer
There's a science to staying warm and comfortable. Start with a thin base layer next to your skin to wick away sweat. Then add a layer of insulation to trap and hold in body heat. Finally, finish with a waterproof outer layer to protect you from the elements.
The Right Add-Ons
Pappalardo recommends investing in a jacket with a reflective, or LED, light to help you stand out from the snow, and a good pair of running tights to hug your leg muscles and keep them insulated. Wear gear that keeps your feet extra dry, like a shoe that wicks away moisture, paired with wool socks or even toe socks from a company like Injinji, which help to further hold in the heat. It's the difference between a mitten and a glove for your toes.