This paper deals with non-contact measurement of temperature in human faces. Principle of measurement of infrared radiation and construction of the thermal imager is described in a literature search. The main part of the paper is design of an algorithm for automatic processing and the detection of regions of interest in thermal images. The theoretical description of used methods is also included in this paper. The aim is to design and implement a program for automatic evaluation of temperature changes in a human face in a sequence of thermal images that were taken with short time delay. As a part of thesis is description of implementation of designed algorithm in programming enviroment MATLAB and the description of the user interface. The program was tested on the experimental data samples. Obtained results and possible limitations are also discused in this paper.