Optical Nanothermometry as a Diagnostic Tool for Diseases: Physical Principles, Challenges, and Limitations

Abstract Variations in temperature often signal pathological changes, including inflammation, cancer, or infections. Examining how quickly temperature changes after the disease onset can offer valuable insights into the body's physiological responses. For successful clinical implementation of thermometry approaches, precise real‐time temperature measurements are required with high spatial resolution, sensitivity, and accuracy, particularly in deeper tissues. This necessity has stimulated advances in optical nanothermometry, which employs light‐responsive agents that alter their optical properties in response to temperature variations. This review examines recent progress in optical nanothermometry as a diagnostic tool for detecting pathological conditions, particularly cancer, inflammation, and disorders of the muscles, heart, and brain. The fundamental principles and techniques of optical thermometry are outlined, and the challenges and limitations of temperature measurements in biological systems are addressed.