In the wake of today's explosions in London, people may be asking themselves an unsettling question: What would I do if I were there?

Dozens of people were killed and hundreds injured in bombings on London's subway trains and a public bus.

It's a problem no one wants to face. But life is unpredictable, and terrorism is no stranger to many countries.

If you find yourself in the wrong place at the wrong time, what should you do?

And when terrorism strikes farther away, how do you stay compassionate without becoming overwhelmed by or numb to horrific events?

Read Web MD's "Americans Unprepared for Psychological Terror."

Safety First

The first tip probably mirrors your gut instinct to put safety first.

"You want to exit the area as quickly as you are physically able," Howard Klausner, MD, tells WebMD.

Klausner is medical director for emergency medical services and disaster medicine at Detroit's Henry Ford Hospital.

"Your overriding response, I think, is going to be your own personal safety and the safety of those around you — trying to assist people to get out of harm's way or out of ground zero," says Alexander Isakov, MD, MPH.

Isakov is an emergency medicine physician and assistant professor of emergency medicine at Emory University.

Read Web MD's "Public Health Experts Plan for the Unthinkable."

Staying Calm

"Stay calm and be patient" tops the American Red Cross list of general disaster guidelines.

But how do you do that in the face of terrorism?

"As a government or a responding agency, of course, the desire would be that people remain calm because the alternative is panic," says Isakov. "Panic isn't going to be really conducive to regaining control and order of the situation."

Predicting how someone might respond would be "very difficult," he says.

"I think to expect that some people will be calm and some people will be terrified and panicked is probably consistent with reality," says Isakov.

Read Web MD's "Coping With Psychological Warfare at Home."

Following Directions

If you're on the scene, follow instructions from local emergency service providers when they arrive, say Klausner and Isakov.

If you're in another part of a town hit by terrorism, you should also comply with government orders, says Isakov.

For instance, he says authorities may ask people to avoid certain areas, minimize their use of personal communications equipment, or stay out of hospitals unless they're victims or in dire medical straits.

Click on the Video Box in the upper right corner of this story to watch an eyewitness account of the London bus bombing.

Helping Others

In the chaos right after a terrorist attack, many people want to help their fellow survivors.

"It's hard to give people advice to not stop and help others, because that is your natural human instinct — to try to render assistance," says Klausner.

"In general, though ... you want to help others only after you have really determined that it is really safe for yourself. That's very difficult to do in a stressful situation," he says.

Some attacks may include secondary devices, say Klausner and Isakov.

"To stay in the area of an event ... might put you at risk of being a victim of a second explosion, if there was such a thing," says Isakov.

"I think people [are] going to make personal determinations about what they think they can accomplish for their new acquaintances at the scene," he says.

"I don't know that there's a good overriding recommendation for them except that when emergency service providers arrive to be compliant with their instructions and their direction."

After a Building Explosion

The Federal Emergency Management Agency (FEMA) posts this advice about building explosions:

—Get under a sturdy table or desk if things are falling around you.

—When those items stop falling, leave quickly. Watch for obviously weakened floors or stairways.

—Don't use elevators in the building.

—Once outside, don't stand by windows or other potential hazards.

—Move away from sidewalks or streets needed by emergency officials or others still leaving the building.

FEMA's advice for those trapped in debris:

—Try to signal rescuers. Whistle, tap on a wall or pipe, or use a flashlight.

—Shout only as a last resort. You could inhale dangerous amounts of dust.

—Avoid unnecessary movement, which could stir up dust.

—Cover your nose and mouth with anything you have on hand. Densely-woven cotton can act as a good filter. Try to breathe through the material.

Emotional Response

Thousands of miles from ground zero, the media bring news of terrorism to our attention. Distance shouldn't exempt us from caring, says Anie Kalayjian, EdD, DSc, RN.

"The key for mental health is to balance that empathy without completely absorbing and feeling and going through the pain and re-experiencing the pain," says Kalayjian.

She is a psychology professor at Fordham University and a Red Cross-certified disaster mental health specialist. Her books include Disaster and Mass Trauma: Global Perspectives on Post Disaster Mental Health Management. Kalayjian also serves as treasurer for the U.N.'s nongovernmental organization committee on human rights.

Read Web MD's "How to Talk to Your Kids About War."

Showing Your Humanity

It's important not to get overwhelmed by or desensitized to such events, says Kalayjian, who was heading to the United Nations after talking to WebMD.

"It is only showing our humanity when we are affected by it," she says. "What affects one person in another country will ultimately affect us."

"We need to be more conscious of that and aware of that and embrace that, instead of rejecting it by presenting ourselves with our daily tasks and not reflecting on the trauma," says Kalayjian.

Planning Ahead

Government officials have repeatedly asked Americans to develop a personal emergency plan and to report suspicious packages and activities.

Planning where your family would meet or communicate could also help in the event of natural disasters, says Isakov.

He encourages people to take fire and disaster drills seriously at work.

"We have to put disaster-planning apathy behind us and take [it] seriously as a health community," he says.

"I think we have to expect that we're going to see more events like we've seen in London and Madrid in our future in the U.S. and be prepared to deal with that," says Isakov.

By Miranda Hitti, reviewed by Brunilda Nazario, MD

SOURCES: Howard Klausner, MD, emergency physician and medical director for emergency medical services and disaster medicine, Henry Ford Hospital. Alexander Isakov, MD, MPH, assistant professor of emergency medicine, Emory University; medical director, Emory Flight. Federal Emergency Management Agency: "Are You Ready? Explosions." American Red Cross: "Terrorism: Preparing for the Unexpected." Anie Kalayjian, EdD, DSc, RN, psychology professor, Fordham University, author, Disaster & Mass Trauma: Global Perspectives on Post Disaster Mental Health Management.