Results of a study of special features of macrolocalization of strain under intermittent yield obtained with the help of thermal imaging and analysis of thermograms are presented. The stage of initiation of strain bands is discovered and detected. It is shown that the beginning of intermittent yield may be preceded by macroscopic nonuniformity of strain, which does not disturb the stability but activates the beginning of band formation. Static loading in the elastoplastic range is shown to be accompanied by a decrease in the temperature. Specific features of the evolution of temperature fields are determined for different serration patterns. It is shown that local heating due to the formation of one strain band can activate the formation of the next band. It is inferred that the method of thermal imaging is very effective for studying special features of plastic strain.