A burn is damage to your body's tissues caused by heat, chemicals, electricity, sunlight or radiation. Scalds from hot liquids and steam, building fires and flammable liquids and gases are the most common causes of burns. There are three types of burns: First-degree burns damage only the outer layer of skin Second-degree burns damage the outer layer and the layer underneath Third-degree burns damage or destroy the deepest layer of skin and tissues underneath Burns can cause swelling, blistering, scarring and, in serious cases, shock and even death. They also can lead to infections because they damage your skin's protective barrier. Antibiotic creams can prevent or treat infections. After a third-degree burn, you need skin or synthetic grafts to cover exposed tissue and encourage new skin to grow. First- and second-degree burns usually heal without grafts.