Thermoluminescent dosimeters (TLDs) are devices used to measure ionizing radiation exposure. They contain materials that store energy from radiation, which is later released as light when heated. The amount of light emitted is proportional to the radiation dose received, allowing for accurate measurement of exposure levels. TLDs are commonly used in various fields, including medical applications, nuclear power plants, and research laboratories. They are favored for their sensitivity, reusability, and ability to provide dose information over extended periods. This makes them valuable tools for monitoring radiation exposure in both occupational and environmental settings.