Third-degree burns are a type of full-thickness burn that damages both the epidermis and dermis. They can occur due to direct skin exposure to heat, steam, radiation, or caustic chemicals for an extended period. The treatment depends on the patient's symptoms, age, and general health, and may involve wound debridement, breathing and blood circulation support, administration of electrolytes and antibiotics, and tetanus vaccine. Prevention is key, as third-degree burns can be prevented by taking safety precautions in risky environments, such as installing smoke alarms and practicing fire escape routes.