The article describes the technique of resource-intensive (in terms of computing resources) and accurate assessment of the thermal mode of electron-ic equipment. The method involves the consist use of software packages “AN-SYS” and “ASONIKA-TM” to calculate temperature pattern that occurs dur-ing operation of the device. Accounting result in “ANSYS” is used as a thermal boundary condition of the first kind for the calculation in “ASONIKA-TM”