Concrete specimens exhibit significant warming during fatigue tests. The specimen temperature can increase by 40 K or even more depending on the amplitude of loading and the load frequency. Newest test results show that this warming of the specimen causes it to fail prematurely. However, no model for estimating the temperature development of cyclically loaded concrete specimens exists as yet. To identify the degree of warming of the specimens and the reasons for it, an energetic-model approach was developed. The present contribution describes the energetic approach and compares its results with those of experimental investigations. For the experimental investigations tests on plain concrete specimens subjected to various amplitudes of loading and load frequencies were carried out.