One minute you could be having a heart attack at Cronig’s Market and several hours later you could be in the recovery room at Massachusetts General Hospital following triple bypass surgery.

Thanks to the critical care transport service Boston Medflight, Islanders with acute medical needs that go beyond what the Martha’s Vineyard Hospital can provide are able to receive top-flight medical care at the major Boston hospitals. A nonprofit, Medflight is part of the consortium of six teaching hospitals in the Boston area, including Massachusetts General Hospital, Beth Israel Deaconess Medical Center, Children’s Hospital, Boston Medical Center, Brigham and Women’s Hospital and Tufts Medical Center.

Vineyard patients who need critical care are sent to one of the hospitals, depending on the speciality needed.

“We act as a linkage for the hospital to the tertiary care centers in Boston,” said Andy Farkas, chief operations manager for Boston Medflight. “These are highly acute medical and trauma cases that exceed the capacity and capabilities of the hospital.”

The service responds to calls from northern Rhode Island to southern New Hampshire, from I-495 East to the Cape and Islands. Between 130 and 140 patients are airlifted off the Island every year, Mr. Farkas said, most of them during the summer. Some days there are none, but on other days as many as three flights can leave the Vineyard hospital in a single day.

In addition to medical evacuations by air, the hospital does about 500 ambulance transfers via ferry annually. Most patients are transported to Massachusetts General Hospital, an affiliate of the Vineyard hospital.

The decision to call in Medflight is made by the attending physician at the hospital or scene of an accident. Medflight will respond if there is potential for loss of life, limb or vision. Doctors on and off-Island determine the best course of treatment as the Medflight team manages the situation. The patient is usually transferred directly to a Boston hospital by helicopter.

Most patients are transported directly from the Vineyard hospital, Mr. Farkas said, although occasionally a transport takes place from the site of an accident.

Medflight has three helicopters, one jet and three critical care ground ambulances. A critical care team including one or two pilots (depending on the vehicle), a critical care nurse and critical care paramedics accompany the response. The fleet is equipped with emergency medical equipment including an intra-aortic balloon pump and neonatal incubator.

Weather conditions may determine which vehicle is used, Mr. Farkas said, and “can really affect the ability to get on the Island.”

Helicopters are preferred for transports, but if visibility is too poor in summer or there are icy conditions in the winter, the jet airplane is used and lands at the Martha’s Vineyard Airport.

“Safety is our primary focus before we come out,” Mr. Farkas said. “Pilots make the determination whether we go or not based on weather and safety. It’s a very sterile decision whether we can go or not.”

Flights leave from an airbase in Plymouth and on average take a little over an hour to come to the Vineyard and then fly to Boston. Medflight helicopters land directly at the Boston area hospital. The jet usually lands at Hanscom Air Force Base near Bedford and transports patients via ambulance to the hospital. There are also air bases in Bedford and Lawrence.

Medflight works cooperatively with other medical air programs in the area. In the event Medflight cannot respond to the Vineyard or cannot respond in a timely fashion, they will coordinate a pickup with another helicopter service.

“We never leave them without a resource on the way,” Mr. Farkas said.

The U.S. Coast Guard helicopter is used as a last resort in severe weather.

All patients are taken on board regardless of their financial situation, Mr. Farkas said. Patients are billed through their insurance carriers. If there is no insurance, no problem.

“We don’t ask for anything up front; we’ll transport them to the place they need to get care,” Mr. Farkas said. “On average we give several million dollars in free [unreimbursed] care.” Timothy Walsh, president and chief executive officer at the Martha’s Vineyard Hospital, praised Medflight, calling it an important piece of the continually evolving critical care services on the Vineyard. Many patients with acute care needs from strokes to severe injuries are sent to Boston for specialty care, he said.

“People say, well they never used to transfer them,” Mr. Walsh said. “Well maybe they didn’t, but they probably should have. It’s not fair to the patient for a primary care doctor to do a workup for something that really needs a specialist.”

For example, patients needing neurology, neurosurgery or cardiology care are all “going to get shipped,” Mr. Walsh said.

Carol Bardwell, chief executive nurse at Martha’s Vineyard Hospital, said despite the visibility of Medflight during times of crisis, the actual number of medical evacuations from the Island is relatively low, thanks in part to the expert work by trained emergency medical personnel, including paramedics.

“It doesn’t happen as much as you would think,” she said. “And to be honest, with the way we have paramedics on the Island now, it’s much easier to get people off by ambulance and ferry if Medflight is not flying.”

But when it’s needed, Medflight is the best way to go, she said.

“It’s a great service,” she said. “They are a group of highly trained individuals. If you have to go, it’s the way you want to go.”