New York City is currently facing a significant cold snap, prompting the National Weather Service to issue a frostbite danger advisory. Temperatures have plummeted to 20°F (-6°C), with wind chills exacerbating the risk of frostbite, which can occur in as little as 30 minutes on exposed skin. The advisory emphasizes the importance of wearing warm clothing, including hats, gloves, and scarves, to protect against the severe cold. Health officials are urging residents to watch for signs of frostbite, such as numbness or discoloration of the skin, and to seek immediate medical attention if suspected.