The Polar Vortex is back with a vengeance.

Yesterday's snowfall kicked off another blast of cold weather for New York, with temperatures expected to remain below freezing until Saturday. But the frigid weather isn't just a nuisance -- in some circumstances, it can also be hazardous to your health. Learn how to protect yourself from frostbite (and its less severe but still troublesome cousin, frostnip) with these tips culled from WebMD:

 

Layer, layer, layer. If you're heading outside in the cold, bundle up in loose-fitting clothes and make sure your hands and ears are covered.

 

Some people are more susceptible to frostbite, including young children, the elderly, patients with diabetes or other circulation problems and people who smoke or consume alcohol while exposed to the cold.

 

Pay attention to your body. If you notice any change of color in your skin (white, red or blue-tinged) or feel a pins-and-needles sensation, get out of the cold immediately

 

To determine if things have progressed into full-blown frostbite, look for skin that's turned white, yellow, gray or black, as well as blisters or patches that feel hard or waxy.

 

Frostnip can be treated at home by submerging the affected area in warm (not hot) water, or in a pinch, by warming the frostnipped skin with your own body heat, such as putting dry hands over an exposed nose. If you suspect frostbite, get emergency medical help as soon as possible.