(CNN) -- During a major storm, the emergency room is eerily quiet. But in the hours afterward, the injured pour in.
Motorists have lost control and gotten into car wrecks. People with underlying conditions have had heart attacks while attempting to dig out of the snow. Others have slipped and slid, fracturing or breaking bones.
For people who rely on daily medications, treatments or home visits, snowstorms can be life threatening.
"For the folks who are bedridden, we're their only lifeline," said Jamie Orsino, who works with the Boston Emergency Medical Services. "They need oxygen, but they can't call an oxygen company because nobody's coming. Visiting nurses don't come in the middle of the storm. The only real lifeline is EMS, no one else will come."
Bustling cities from Boston, Massachusetts, to Atlanta, Georgia, froze to a standstill and roadways were encased in ice. Officials declared snow emergencies, schools and businesses closed, and more than 1,700 flights were canceled.
With supply chains disrupted and icy roads preventing staff from getting to work, hospitals, like Emory Healthcare in Atlanta, have canceled elective surgeries and are monitoring their medicine supply.
"There are concerns about adequacy of blood supply and pharmaceuticals," said Dr. Kate Heilpern, professor and chair of the Department of Emergency Medicine at the Emory School of Medicine, which oversees five metro Atlanta hospitals. "We've had to institute internal disaster protocol plans."
Hospitals plan for natural disasters or weather emergencies by rationing medicine and having staff stay in nearby hotels or in hospital rooms.
Heilpern said the injuries commonly seen are fractures, other injuries related to car crashes, and cold-related problems. While the volume of patients hasn't been higher, Heilpern said the hospitals were "expecting a surge in volume as the week progresses."
During snowstorms, people with chronic health issues such as end-stage renal disease have nowhere else to go for help, because their dialysis centers are closed. And many pharmacies and stores are shut, too.
"If you can't get to the pharmacy and it's a critical life-sustaining medication, the emergency department is your only bet," said Dr. Leigh Vinocur, a spokeswoman for the American College of Emergency Physicians.
The wait at the emergency room may not be longer than usual, because people with less pressing health needs opt to stay home, deterred by bad road conditions, said Vinocur, an emergency physician at the University of Maryland School of Medicine in Baltimore.
But emergency departments can face issues of crowding as discharged patients can't leave because they have no safe way of getting home. Also, the homeless who are unable to find shelter come to hospitals with cold-related issues such as hypothermia, doctors said.
For emergency responders, the biggest obstacle is navigating through the maze of ice slicks and car accidents.
The Northeast region may be better equipped to handle storm cleanup than the South, but such cold weather experience does not guarantee success.
Just after Christmas, New York City grappled with the fifth-largest storm in the state's history. Ambulances lodged in the snow couldn't pick up patients. Thousand of calls to emergency dispatchers were backlogged. In one instance, a newborn died in Brooklyn after the mother waited nine hours for emergency responders.
New York's EMS chief was replaced after that debacle.
Patrick Bahnken, president of the union that represents New York's EMTs and paramedics, said the December backlog occurred because so many vehicles were stranded, blocking snowplows, which made it difficult for ambulances to get through.
"All those things exacerbate our ability to react in an emergency," he said.
"We are used to snowstorms," Bahnken said. "Most of the time, it goes smoothly without a hitch. On occasion, a snowstorm gets away from you. Your reaction time is disrupted. Once you start losing control, it becomes a cascading effect, and it snowballs."
He warned drivers to stay off the roads, because car accidents can block passage for emergency responders.
"The odds are good you are not going to get to where you need to go," said Bahnken. "You're going to tax an overtaxed system."