Which of the following is a sign of shock?

Cool, clammy skin is indeed a significant indicator of shock. In a state of shock, the body is not receiving adequate blood flow, which leads to compromised circulation and results in a decrease in skin temperature. This vasoconstriction, which is a body response to maintain blood flow to vital organs, often leads to the skin feeling cool and may also appear pale or clammy due to moisture accumulation.

The other options do not align with the physiological changes typically associated with shock. For instance, increased blood pressure is not a sign of shock; in fact, blood pressure often drops as shock progresses. Similarly, while a rapid heart rate may occur in reaction to shock as the body attempts to maintain blood flow, it is not a standalone sign and is more indicative of a physiological response rather than a direct sign of shock itself. High fever can indicate an infection or other medical conditions but is not a characteristic of shock. Understanding these signs can help in recognizing patients in critical conditions and facilitating timely and appropriate medical response.