Which form of tissue damage is due to heat buildup, often described as the cooking effect?

• A. Photomechanical
• B. Photochemical
• C. Photothermal
• D. Thermal

Answer: (D)

Thermal damage occurs when tissue temperature rises enough to cause proteins to denature and cell structures to coagulate, much like cooking. This heat buildup damages cells regardless of how the heat is delivered, and the severity depends on both the peak temperature and how long it lasts. While other options involve heat produced specifically by light (photothermal) or damage from light-triggered chemical or mechanical effects (photochemical, photomechanical), the broad description of damage from heat buildup itself is thermal.