A Wind Chill Advisory has been issued for Central Maryland, including Manchester, MD.  According to the National Weather Service:

…WIND CHILL ADVISORY REMAINS IN EFFECT UNTIL NOON EST TODAY…
…WIND CHILL ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO 6 AM
EST SUNDAY…

* WHAT…Very cold wind chills expected. The cold wind chills will
cause frostbite in as little as 30 minutes to exposed skin.
Expect wind chills to range from 5 to 15 below zero.

* WHERE…Portions of northern Maryland, northern Virginia, and
eastern West Virginia.

* WHEN…For the Wind Chill Advisory, until noon EST today…and
again from 6 PM this evening to 6 AM EST Sunday.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

A Wind Chill Advisory means that cold air and the wind will
combine to create low wind chills. Frost bite and hypothermia can
occur if precautions are not taken. Make sure you wear a hat and
gloves.