In volatile times, violent events can sometimes happen close to home.

Anyone might be called upon to help another person injured in a mass assault.

Just ask people in Orlando, where 49 people were killed in a mass shooting inside a club by a lone gunman last month.

Or the employees of a San Bernardino County office building, where 14 people were fatally shot by two assailants in early December.

Or the people who were protesting on the streets of Dallas early this month when five police officers were gunned down by a sniper situated in a parking garage.

What would you do if you suddenly found yourself near assault victims?

Next to people needing immediate help — your help — until police or emergency medical services (EMS) arrive.

Read more: Why are we afraid of being a victim of a mass shooting? »

First thing: Be safe

Healthline spoke with emergency medical doctors at major medical centers in San Francisco and New York, as well as an expert who helps direct the work of the fire department EMS in Washington.

Their answer: Most of us, even without training, can help in simple but crucial and effective ways.

“The absolute first thing you should do if you are near a victim or victims of a violent crime is to ensure that you are safe,” Dr. Mary Mercer said.

Mercer is assistant clinical professor of emergency medicine at the University of California, San Francisco, and EMS Base Hospital medical director at Zuckerberg San Francisco General Hospital.

“Make sure the assailant has left the area and there is no obvious threat to you,” she said, “You will be no help to the victims if you get injured or killed in the process of trying to help them.”

If you believe the assailant is still nearby or that there is an active threat, she said, you should “shelter in place, which means try to take cover or hide near where you are,” or try to run away to safety if you think it is safe to do so.

Read more: Learn the basics of first aid »

Second step: Call for help

Getting help is the next crucial step.

Dial 911 from a landline or cell phone, and be prepared to be as specific as possible about your location, Mercer said.

Emergency dispatchers may need information about cross streets, or specifics about the apartment or office building you’re in. Provide details about the floor you are on and room numbers, if possible.

“This will help the rescuers get to you and the victims as quickly as possible,” Mercer said. “The 911 dispatcher also may give you instructions about how to help the victims you are with. Listen to them and follow their instructions.”

If you are traveling in a foreign country, it is wise to research the local emergency numbers and procedures ahead of time, and to write them down or program them into your phone, Mercer said.

This information usually can be found at the front of travel guides and on the U.S. State Department website.

After you have ensured your safety and called for help, or enlisted others to do so, you can turn your attention to helping the injured.

Dr. Neha Puppala, assistant medical director for the District of Columbia Fire Department and EMS, recommends following the FBI guidelines for such situations.

The guide, called Run-Hide-Fight, is detailed in a downloadable pocket checklist.

“Then from a medical perspective, if you are able to reach the victim, you will have to decide whether that person is safe remaining where he or she is. And if not, whether you can move the person to a safer location,” she said.

Puppala added that you should consider the risk of becoming a victim yourself, and whether you may further harm the victim by moving them.

“We encourage reassuring the victim that help is coming and that they will be OK,” she said.

Read more: First aid for children »

Third step: Stop the bleeding

Stopping the bleeding may sound simple, but trying to help in the wrong way can hurt rather than help.

“Hemorrhage control is about identifying and minimizing or stopping life-threatening blood loss,” Puppala said. “Untrained bystanders can help by applying pressure to wounds or using a tourniquet, if trained to do so.”

Improperly applied tourniquets may cause more harm to the victim.

In trauma situations, EMS personnel use the acronym X-A-B-C as a checklist that ranks the crucial order of response: Hemorrhage Control-Airway-Breathing-Circulation.

Mercer said first you control any bleeding. Then, if the victim is unconscious, you can try to address "A" (airway) and "B" (breathing) by opening the person's mouth to see if that helps them start to breathe.

“If the victim is a child, and after you open their mouth they are still not breathing, you can try giving two rescue breaths to see if that helps,” she said.

Puppala recommends taking a first responder class to learn more about hemorrhage control, including tourniquet application, or the subsequent steps of X-A-B-C.

Classes are often available through local Red Cross chapters and county health departments.

Read more: First aid for unconsciousness »

Moving a victim carefully

Moving a person to safety might be your first reaction during an assault, but it’s not necessarily the best option.

“When you need to move a patient out of harm’s way, if they are a victim of trauma you must remember that they might have a spinal fracture, and if you move them incorrectly that might render them paralyzed,” said Dr. David Barlas, assistant professor of emergency medicine, and chief of New York University Langone Medical Center’s Cobble Hill Emergency Department in Brooklyn.

“If there is no other option and you have to move someone, the most important thing to do is position them on a rigid board of sorts and maintain alignment of their neck and head with their body,” he told Healthline. “Once stabilized on the board, secure them with a belt, sheet, rope [or whatever else may be available], and move them from the dangerous location.”

Read more: Emergency rooms facing shortages of important drugs »

What should you definitely not do?

One of the most common mistakes is sitting the patient upright.

Barlas said moving a victim in an uncontrolled way could cause greater injury.

“If someone is bleeding from a gunshot wound, you want to leave them in a supine (lying down) position,” he said. “You do this to keep oxygen flowing to the brain. If you sit them up the head becomes the highest point, and you may get less blood flow to the brain. The patient could pass out or get worse. Don’t move the patient unless you absolutely have to.”

If a patient is losing a lot of blood, elevate the legs. This could improve blood flow to the brain because more blood will flow into the body, Barlas said. That will enable the body to help itself by giving more blood to the brain and vital organs.

Puppala listed other “don’ts” to consider.

Do not push or pull on things that are in or sticking out of the body. Leave objects that are penetrating the body in place, and try to minimize movement of these objects.

Do not try to explore wounds. Apply a dressing if possible and hold steady pressure, but do not try to push anything into the wound.

Try not to force the victim into a certain position. Allow the victim to relay to you what is most comfortable for them. This may be a clue to their injuries.

If you’re worried about liability, Mercer said American “Good Samaritan” laws protect bystanders who try to help victims in emergencies.

There are differences from state to state, though.