We have experimentally determined the temperature dependences of the refractive index and thermal conductivity for several optical disk materials from room temperature to 200-300 degrees C. A novel system for obtaining thermal conductivity in the films is also introduced. As a demonstration, temperature simulation inside a simple-structured disk with and without considerating the temperature dependence of the refractive index at a 405 nm wavelength was carried out, and the difference was approximately 15 degrees C at maximum temperature.