Which sign is associated with first degree burns?

First-degree burns are characterized primarily by pain and redness in the affected area. These burns affect only the outer layer of the skin, known as the epidermis, and typically present as a painful area that may be swollen but does not form blisters. This is consistent with the symptoms of mild burns, where the skin may appear red or pink but remains intact.

The option of painful and swollen area accurately describes the typical presentation of first-degree burns. It highlights the skin's inflammatory response, which includes increased blood flow and fluid retention in the tissues, leading to swelling and sensitivity to touch or temperature.

In contrast, the other choices display signs of burns that are either more severe or categorize different burn types. Open and closed blisters are associated with second-degree burns, where the injury extends deeper into the skin layers. Brown or charred skin indicates damage consistent with third-degree burns, which destroy both the epidermis and underlying layers, leading to a loss of sensation in that area. Cool, moist skin can be indicative of shock or other conditions but is not a classic sign of any burn type. Therefore, the description that correlates specifically with first-degree burns is the presence of a painful and swollen area.