On July 6, 2007, a 34-year old male, career, Fire Fighter-Technician responded to three emergency calls, performed a fire prevention inspection, and attended training during his shift. About six hours after his emergency response, the FF-Technician experienced chest pain and shortness of breath. He alerted the Station's paramedic who initiated treatment prior to transport to the nearest hospital. An "evolving anterior myocardial infarction [heart attack]" was diagnosed and the FF-Technician was flown to a tertiary care hospital for a cardiac catheterization and possible angioplasty. Upon arrival in the cardiac catheterization laboratory, the FF-Technician went into cardiac arrest. Despite cardiopulmonary resuscitation (CPR) and advanced life support, including placement of an intra-aortic balloon pump, the FF-Technician died. The death certificate and autopsy, completed by the Deputy Medical Examiner, listed "myocardial infarct" as the immediate cause of death due to "hypertensive cardiovascular disease." NIOSH investigators agree with this determination, but cannot rule out the possibility of cardiomyopathy. In either case, the FF-Technician's fatal incident was probably triggered by the heat and physical stress of responding to the emergency calls during his shift. NIOSH investigators offer the following recommendations to reduce the risk of on-duty heart attacks and sudden cardiac deaths in this and other fire departments across the country. 1. Modify the current fitness-wellness program to be consistent with NFPA 1583, Standard on Health-Related Fitness Programs for Fire Fighters and the Fire Service Joint Labor Management Wellness/Fitness Initiative to reduce risk factors for cardiovascular disease and improve cardiovascular capacity. 2. Secure funding from the governing municipality to upgrade the current fitness-wellness program. 3. Consider symptom-limiting stress tests for fire fighters at increased risk for coronary artery disease and sudden cardiac death. 4. Adopt NFPA 1582: Standard on Comprehensive Occupational Medicine Program for Fire Departments to ensure fire fighters have the medical ability to perform duties without presenting a significant risk to the safety and health of themselves or others. 5. Work with the local union to phase-in an annual physical ability test.