Final answer:
The man's symptoms indicate a potential heart attack, and the most appropriate action is to d) immediately activate the emergency medical system (EMS). While nitroglycerin and gathering medical information are important, they come secondary to urgent medical intervention.
Step-by-step explanation:
The symptoms described by the 63-year-old man, including substernal chest pain radiating to his left arm and jaw, along with a high pain scale rating, are indicative of acute myocardial infarction (MI), commonly known as a heart attack. Given that he is experiencing what could be unstable angina, immediately activating the emergency medical system (EMS) is the most critical first step. This ensures the patient receives immediate medical attention, which is necessary for conditions posing serious risks such as heart attacks.
Providing nitroglycerin may be appropriate if the patient were in a healthcare setting with the ability to monitor his response; however, it does not replace the urgency of EMS activation. A thorough physical exam and obtaining a detailed medical history are important but secondary to the immediate need for emergency medical care.
Failing to act promptly could lead to severe complications or death. The presence of classic symptoms such as radiating chest pain and physiological stress evidenced by a rapid pulse suggest that the patient could be suffering from a severe cardiac event requiring urgent intervention.