A present invention provides real-time temperature and power mapping of fully operating electronic devices. The method utilizes infrared (IR) temperature imaging, while an IR-transparent coolant flows through a specially designed cell directly over the electronic device. In order to determine the chip power distributions the individual temperature fields for each heat source of a given power and size on the chip (as realized by a scanning focused laser beam) are measured under the same cooling conditions. Then the measured chip temperature distribution is represented as a superposition of the temperature fields of these individual heat sources and the corresponding power distribution is calculated with a set of linear equations.