Burns are injuries to tissues caused by which of the following?

• A. Chemical exposure
• B. Friction
• C. Electrical current
• D. Heat contact

Answer: (D)

Burns occur when tissue is damaged by heat energy transferring from a hot source to the skin and deeper tissues. The heat denatures proteins, disrupts cell membranes, and damages cells, causing tissue death and the characteristic injury seen in burns. The severity depends on how hot the source is and how long contact lasts, as well as how thick the tissue is. Hot liquids, steam, flames, and contact with hot objects are classic ways heat transfers to tissue to cause a burn. Other forms of tissue injury exist—chemical burns from caustic substances, electrical burns from current, and friction injuries from rubbing forcefully—but they involve different mechanisms. The direct heat contact mechanism is the most typical route for burns.