The arctic winds and frigid temperatures now experienced across the region aren't just unpleasant, but actually dangerous, according to medical experts.
"Stay indoors, stay warm, check on your loved ones," said Dr. Charles Barbera, emergency services chairman at Reading Hospital.
Barbera said frostbite - a condition caused when skin and tissue freezes, cutting off blood flow - is a rising concern. Hypothermia is also possible, resulting when body temperature drops too low for vital processes to function.
"That happens many times when people are not protected from the cold," said Barbera. "A lot of the things that your body does to generate heat are lost."
Symptoms can range from tiredness to dizziness to confusion.
Barbera told 69 News that both children and the elderly are most at-risk. Those with heart conditions may also experience complications caused by the cold.
"The cold adds an extra stress on the heart. The heart needs to pump more, work harder in the colder weather," said Barbera.
But for those who need to be outside, Barbera suggests bundling up as much as possible, especially covering toes, fingers and the nose - areas more prone to frost bite. He also advises people to avoid alcohol and other dehydrating substances that increase the risk of cold-caused illnesses.
Experts said cold weather is also dangerous for pets.
"If it's too cold for you to be outside, it's too cold for your pets to be outside," said Beth Ireland, director of marketing for the Berks Animal Rescue League.
Ireland told 69 News animals cannot only freeze to death, but can die or become sick from ingesting salt mix or other winter treatments applied outdoors.
For pets who need to be outside, however, Ireland suggests upping their protein intake, which "will help their muscle mass and improve their coat."