The thermointerferometric method for the investigation of materials and thermo-optical phenomena is presented. It makes it possible to determine the thermal interaction-surface deformations and changes of optical properties of objects subjected to thermal load. The method is based on the registration of the temperature distribution on the object surface using a thermovision camera and simultaneous interferometric measurement of the wavefront reflected from the front surface or transmitted through the object. The latter measurement monitors the changes of the surface shape and its optical properties. The experimental setup is presented as well as the methodology of data acquisition, evaluation and presentation. Some considerations of the range of applications and perspectives are also given. These are based on the analysis of experiments verifying the application of the method to investigation.