Not necessarily, suggests a study from the University of Utah School of Medicine in Salt Lake City. But you should! Researchers weren’t surprised when, in a survey of nearly 1,000 people, 9 out of 10 said that they’d call for help if they witnessed someone having a heart attack. But when the researchers looked at 875 people who got emergency room care for chest pain, they were dismayed: Sixteen percent drove themselves to the ER! And only one-third used emergency medical services (EMS) to get there.  “If you’re alone and you can reach the telephone, don’t hesitate to get help,” says study coauthor N. Clay Mann, PhD, associate professor at the university. “Your life is worth the phone call.” Here’s how to be your own best friend if heart attack symptoms strike (the same goes for other medical emergencies too): Call now. If you experience any unusual combination of symptoms for longer than 15 minutes, get emergency help, says Dr. Mann. Conscious heart attack victims often delay acting if they’re unsure of their symptoms and what they mean. They may reach for a pill—antacids or pain relievers—instead of the phone. (It’s appropriate to chew an aspirin once you’ve made the call and are waiting for EMS to arrive.) Or they may call their family doctor, calm down, and drive to the ER instead of relying on an ambulance. Trust the system. EMS can usually reach you—and start treatment—faster than you can get to the hospital. Another benefit: EMS staff will alert the ER to your imminent arrival, reducing the time spent waiting for treatment at the hospital. More from Prevention: 7 Sneaky Signs Of A Heart Attack