Contrary to the assumptions made in previous estimates, next-generation tokamaks are now characterized by lower beta, elevated temperatures (current drive, density limit), and imperfectly reflecting walls (graphite, ceramics). All these features lead to an enhancement of cyclotron radiation losses in relation to, for instance, bremsstrahlung losses. The impact of cyclotron radiation losses on the performance of next-generation tokamaks is rediscussed in the light of these effects. Graphite and silicon carbide (SiC) are considered as typical candidates for weakly and strongly absorbing wall materials, respectively. Various Next European Torus configurations and operation scenarios are taken as representative examples to study the problems relating to plasma performance. The physics of microwave absorption in solid media is reviewed, and various graphite and SiC-based solutions are analyzed. The thermomechanical impact of a volumetric load is also discussed. If all these effects are combined (〈T〉 = 15 keV, weakly or strongly absorbing wall), bremsstrahlung losses and cyclotron radiation losses become comparable and the latter are no longer negligible. In the case of a strongly absorbing wall, cyclotron radiation losses even exceed bremsstrahlung losses by 50%. Due to the strong temperature dependence, cyclotron radiation losses provide a considerable stabilizing effect on thermal runaway. This may provide full stabilization in the case of a favorable confinement scaling or reduce the growth rate to an extent that simplifies application of active stabilization schemes.