A burn or scald means tissue damage caused by heat or a corrosive substance. The most common cause of scalds is hot water. The most important first aid measure is to cool the injured area. Small burns and scalds can be treated at home.
The longer the exposure and the hotter the source of injury, the more extensive the damage to the tissues and severe the burn. Burns and scalds are divided into categories depending on the degree of their severity and their extent is estimated on the basis of percentage of damaged skin of the total body surface area. Common causes of burns and scalds include hot objects, hot liquids and steam, open fire, electricity, chemicals or corrosive substances, or radiation (such as UV radiation from the sun).