An asymptotic description of the evolution of high-frequency large-amplitude plasma fluctuations is obtained in the framework of magnetohydrodynamics with allowance for heat transport. A set of model equations is derived for a bounded plasma both with a fixed and with a free boundary. In the approximation of a strong longitudinal magnetic field, this system is transformed into equations that generalize the Kadomtsev-Pogutse equations, taking into account the toroidal effects, heat transport, interaction between high-frequency and low-frequency modes, and a number of other effects.