What is a key sign of a potential heart attack in a patient?

A key sign of a potential heart attack in a patient is pain in the left arm. This symptom is often related to the heart due to the way pain can radiate from the chest to other areas of the body. The left arm pain occurs because the nerves that carry signals from the heart and the left arm may overlap, leading to the phenomenon known as referred pain. It is important for responders to recognize this symptom, as it can help facilitate timely medical intervention.

In contrast, swelling of the legs typically indicates issues related to circulation or heart failure but is not a classic sign of an acute heart attack. Decreased body temperature can suggest various health problems but is not a specific indicator of a heart attack. Redness of the skin can signify a different range of conditions, including infections or allergic reactions, but it does not specifically correlate with heart attacks. Understanding these signs can make a significant difference in patient outcomes during emergencies.