The micromechanism of the thermoelastic effect (changes in temperature of a solid on its adiabatic elastic loading) is treated using the model of a loaded anharmonic oscillator. Loading leads to changes in frequency and, hence, to changes in the oscillation energy of the oscillators, thereby changing the temperature of a solid. The complicated energetics of loading of an excited anharmonic oscillator associated with conversion of the oscillation energy into static potential energy, and the reverse process, is described. Relevant problems are discussed.