Which of the following is a sign of severe bleeding?

Severe bleeding is characterized by the presence of bright red, spurting blood. This type of bleeding typically indicates arterial hemorrhage, where blood is ejected with force due to high pressure from the artery. This spurting can be periodic with the pulse of the heart and is a clear and immediate sign that the situation is critical, requiring urgent medical intervention to prevent shock and potentially save the life of the casualty.

Other signs of severe bleeding would also include symptoms like pale skin, rapid breathing, and a drop in blood pressure, but the bright red, spurting nature of the blood is the most immediate and visible indicator to recognize the severity of the situation. It demands immediate action, including controlling the bleeding through direct pressure, elevation, or applying a tourniquet if necessary.

In contrast, options that mention low heart rate and cool extremities or increased appetite do not typically correlate with severe bleeding. A low heart rate may suggest bradycardia, which isn't inherently associated with severe blood loss, while cool extremities could indicate other forms of shock but are not exclusive signs of active, severe bleeding. Increased appetite is not relevant in the context of this question regarding acute medical emergencies such as severe bleeding.