Which sign of inflammation is characterized by warmth in the affected area?

The sign of inflammation characterized by warmth in the affected area is heat. Inflammation is a biological response of tissues to harmful stimuli, and warmth occurs due to increased blood flow to the inflamed region. This is often a result of the body's immune response, where blood vessels dilate to allow more immune cells to reach the site of injury or infection. The increased metabolic activity and blood flow can lead to a noticeable increase in temperature, contributing to the feeling of warmth.

The presence of heat is one of the classic signs of inflammation, alongside pain, redness, and swelling. Each of these signs reflects different aspects of the inflammatory process, but heat specifically denotes the increased blood circulation and metabolic activity in the affected tissues.