Which of the following is a sign of infection in an open wound?

Warmth around the wound is a clear sign of infection. When tissue becomes infected, the body's immune response is activated, leading to increased blood flow in the area. This increase in blood flow can cause the skin surrounding the wound to become warm to the touch. This warmth is due to various processes involved in the inflammatory response as the body attempts to fight off infection, such as increased metabolic activity and increased white blood cell presence.

Pale skin around the wound typically indicates reduced blood flow or poor circulation and is not associated with infection. Clear drainage from the wound may suggest that the wound is healing properly, as it implies that there is no pus or infection present. Little to no pain could suggest effective healing or possibly a severe condition where nerve damage has occurred, rather than indicating infection. Thus, warmth is a key recognizable symptom pointing towards an infection in an open wound.