What is a key indicator of someone who has stopped breathing?

The presence of blue lips is a key indicator of someone who has stopped breathing, a condition known as cyanosis. This occurs when the body is deprived of adequate oxygen, leading to a change in skin coloration. When breathing ceases, tissues are unable to receive oxygen, which can cause a bluish tint around the lips and sometimes the extremities. This symptom is crucial for first responders and medical personnel in identifying life-threatening situations requiring immediate intervention.

High temperature, cold sweats, and flushed skin are not direct indicators of someone who has stopped breathing. While they may signify various conditions or responses, such as fever or shock, they do not specifically indicate respiratory failure. In an emergency context, the bluish coloring of the lips is a clear and critical signal that demands swift action to restore breathing and ensure oxygen supply to the body.