The document provides instructions for what to do if experiencing a heart attack while alone in a car. It advises to not panic, but to start coughing repeatedly and taking deep breaths before each cough. This is because coughing squeezes the heart and keeps blood circulating, while deep breaths get oxygen into the lungs. This technique can help the heart regain its normal rhythm until help arrives or the symptoms subside, and potentially save the person's life. The document stresses sharing this information widely as it could help others survive a heart attack even when alone.