Many areas have enjoyed a recent reprieve from what has become a routine of heavy snowfall every few days, but a blast of frigid air sweeping across the region today portends a new round of hazards as freshly melted snow freezes again and coats roads and walkways with a fresh layer of ice.

Additional Photos

In this Feb. 2 photo, Harry Eastman shovels the snow off his garage roof in Barre, Vt. Doctors across the Northeast are seeing a spike in strained muscles from shoveling snow, broken bones from slick stairs and sidewalks, and dangerously low blood banks as fewer people venture out. AP

At Hartford Hospital in Connecticut’s capital, about two dozen people have been treated in the past week alone after falling off roofs and ladders while trying to clear snow. Others have lost fingers in snow-blower accidents, a few have suffered heart attacks while shoveling, and some have been sidelined with broken limbs after slipping on ice.

“We’ve seen this before, but never in these huge numbers,” said Dr. A.J. Smally, the hospital’s emergency department director. “It’s an epidemic.”

Among the Northeastern casualties is Sean Hansell of Valley Stream, N.Y., who said he twisted his neck Tuesday as he tried to recover his balance while slipping on a patch of ice during his daily walk to a train station on New York’s Long Island.

“Oh irony,” he posted on Twitter. “As I’m admiring all the melting snow, I slip on some ice and tweak my neck. Ow.”

The injuries have mounted with each big storm in a season that not even two months in has already buried many Eastern cities with far more snow than they typically see all winter. But in some cases, one man’s loss is a chiropractor’s gain.

An office in Hackensack, N.J., reported more patients than usual this year as people revive old aches and pains while shoveling snow.

“People are forgetting to bend their knees,” said Jo Ann Gouveia, the office manager at Advanced Health Care.

Dr. Karen Erickson, a chiropractor in New York City, said some of her patients have been suffering muscle stiffness because icy sidewalks have kept them from exercising.

“There are a lot of people who get exercise by walking or running, and they’re just not doing it,” she said.

Graphic designer Brian Emling, 27, laughed off a holiday gift of rubber and metal snow treads for his feet. He stopped laughing – and started wearing them – after slipping on ice last week outside his apartment complex in Streetsboro, Ohio, and hitting his right arm.

He was afraid he might lose his livelihood.

“That’s the one thing that races through the mind as soon as you hit your hand: ‘Am I going to be in a cast? Will it impair my ability to do my job?'” said Emling, eventually found to have only a bruise.

It’s true that the East’s relentless snow and ice storms have increased the risk of health problems, including asthma attacks, heart attacks, falls and car crashes, said Wallace Carter, associate medical director of emergency medicine at New York-Presbyterian Hospital.

Before last week’s ice storm, he noted, the New York area had already suffered through nine snowstorms.

“The collective risk to the population is nine times greater than it was if you have one snowstorm,” Carter said.

And as the risk for injuries has jumped, supplies of a critical necessity have dropped nationwide: blood donations.

The American Red Cross says that from Jan. 1 through Feb. 1, it missed out on more than 19,000 blood donations it had expected to get. It blames blood drives scheduled for schools, businesses and community events that were postponed because of the weather.

“This storm is not going to help the situation,” spokeswoman Laura Howe said as the Midwest was hammered by snow recently. “As soon as we get the blood products in the door, they go back out.”

With more than another month of winter to go, conditions aren’t expected to improve soon.

A cold front will send temperatures plunging into the single digits across much of the Northeast today and create icy, treacherous conditions on untreated roads and sidewalks, said Charlie Foley, a National Weather Service meteorologist based in Taunton, Mass.

“Where there’s any melting today – and there is melting – it’s going to freeze,” he said.