The Definition of Burn Injury
A burn injury is tissue damage caused by heat, chemicals, electricity, or radiation, classified by degree based on severity.
A burn injury is tissue damage caused by heat, chemicals, electricity, or radiation, classified by degree based on severity.

A burn injury is damage to skin or underlying tissue caused by exposure to heat, chemicals, electricity, friction, or radiation. Burns are typically classified by degree based on depth and severity: first-degree burns affect only the outer skin layer, second-degree burns extend into deeper skin layers and often cause blistering, and third-degree burns destroy the full thickness of skin and can damage underlying tissue, nerves, and muscle. Workplace burn hazards vary widely by industry and can arise from hot surfaces or liquids, open flames, chemical contact, electrical arc flash, or steam, making burn prevention a relevant concern across manufacturing, food service, construction, and many other sectors.
A line cook reaches across a hot stovetop and makes brief contact with a hot pan handle, resulting in a first-degree burn to the palm; the facility's first-aid station provides immediate cool-water treatment, and the incident is documented per the restaurant's injury reporting procedure.
Burns are commonly classified into first-degree (affecting only the outer skin layer, causing redness and pain), second-degree (extending into deeper skin layers, often with blistering), and third-degree (full-thickness burns that destroy skin and can damage underlying tissue), with some classification systems including a fourth-degree category for burns extending into muscle or bone.
Common causes include contact with hot surfaces or liquids, exposure to open flames or sparks, chemical burns from corrosive substances, electrical burns from arc flash or contact with energized equipment, and steam burns in industrial or food service settings.
Standard first-aid guidance for a minor thermal burn typically includes cooling the area with cool (not ice-cold) running water for several minutes, covering the burn with a clean, non-stick dressing, and seeking medical attention for burns that are large, deep, located on sensitive areas, or show signs of infection.