As you can imagine, first responders in Las Vegas have been working around the clock since the mass shooting in Las Vegas on Sunday night. The area hospitals are inundated with patients.

"Your day-to-day work goes out the window, this becomes your work that day," said Dr. Bill Morgan, a trauma surgeon with Saint Alphonsus in Boise.

Hospitals only have so many rooms and so many beds.

"One of the things that probably got done up front was who can we move out, who can we send home, who doesn't really require the hospital care," said Dr. Morgan.

Then police, paramedics, and firemen do what's called field triage.

"That means they're looking at all the patients and they're saying this patient is sick enough that they need someplace where an operation can save their life, and this patient may not be able to be salvaged," Dr. Morgan said.

MORE: Local residents recount bloody chaos in Las Vegas; 1 Idahoan shot

Dr. Morgan says in Idaho a mass casualty incident, or MCI, is anything more than five patients.

"Once you get to five patients you begin to push the hospital's capability to manage those patients in the emergency room," Dr. Morgan said.

After finding out how many surgeons are available to respond to the incident, the hospital finds out how many operating rooms are available.

"We would check with the operating room," said Dr. Morgan. "How many operating rooms do you have open, how many operating rooms are coming close to where you might be able to get the patient out of the operating room and complete their surgery so that we can use that operating room."

The next move, Dr. Morgan says, would be finding what other facilities in the area have surgical capabilities and space.

"They're going to tie up your ICU resources, they're going to tie up your operating room, your anesthesia resources, your blood, your blood products," said Dr. Morgan. "There's a lot of things that go into that."

MORE: Meridian couple caught in Las Vegas horror: "I was sure we were going to die"

With so many steps, moving parts and procedures in place, it's the planning that truly makes the difference when something like the shooting in Las Vegas happens.

"It is probably the most important thing that we would do," said Dr. Morgan.

Lisa Spanberger, St. Luke's Disaster Preparedness Emergency manager, says they focus on an all hazards plan.

"So being able to be prepared and trained, educated on any disaster that could strike in our area," said Spanberger.

She says the starting step is building strong relationships with local law enforcement and emergency responders.

"So how we're going to be able to utilize the resources we have here at the facility but also leverage our community partnerships," Spanberger said.

Spanberger says the response doesn't stop after once everyone has been admitted to the hospital.

"While we are responding and taking in casualties, we're also being able to comfort families, offer social support and also being able to work with Ada County Coroner and Canyon County Coroner to be able to work with the fatalities," Spanberger said.

Both Saint Alphonsus and St. Luke's say they would utilize each other's resources if necessary. Both hospitals also undergo annual emergency training.