Almost everyone suffers a burn from time to time. Most are common heat burns caused by hot objects or liquids, steam or fire. Children and elderly people are the most susceptible to these, but anyone can suffer these types of burns. They are typically first-degree burns, which affect the top layer of skin. Second-degree burns injure the first and second layers, while third- and fourth-degree burns go deeper and require immediate medical treatment. Heat, however, is by no means the only cause of such injuries.