Partial-thickness burns caused by chemicals, flame, or hot liquids damage the epidermis and part of the dermis. These second-degree burns appear as fluid-filled vesicles that are red and shiny (and wet if the vesicles have ruptured). Symptoms include edema, hyperesthesia, pain caused by nerve injury, and sensitivity to cold air. Healing typically takes 10 to 21 days for superficial partial-thickness burns, which involve part of the dermis, and 2 to 6 weeks for deep partial-thickness burns, which involve more of the dermis.