(1) general thermal burns: burns caused by hot liquids (hot water, hot porridge, hot soup, hot feed, etc.), hot ash, steam, high-temperature metals (solid, liquid), thermal pressure, flame, etc. (2) chemical burns: acid, alkali, phosphorus, ethanol, Louis gas, gas explosions and other injuries. (3) electrical burns: arc burns, electrical contact burns, flash burns, etc. (4) radiation burns. Of the above burn factors, general thermal burns account for about 80%.