For safe and sound utilization of the applications made of polylactic acid that output an electric signal to an intended mechanical input within an undesirable thermal environment, the transient thermoelectroelastic field is investigated for an infinite cylinder with D ∞ symmetry subjected to shear stress as an intended mechanical input and temperature as an unfavorable thermal environment. By use of the analytical technique constructed previously, the field quantities are represented in terms of the elastic, piezoelastic, and thermoelastic displacement potential functions and the electric potential function, and the governing equations for these functions are presented. Then, the analytical solutions of the transient and non-axisymmetric field quantities are obtained using the Fourier and Laplace transformations with respect to the axial coordinate and time variable, respectively, and the Fourier expansion with respect to the circumferential coordinate. Subsequently, numerical calculations are performed to investigate the field due to the shear stress or temperature. As a result, the structures of respective fields are elucidated and the effect of thermal disturbance on the output signal to mechanical input is investigated quantitatively, both of which illustrate the significance of transient and three-dimensional analysis.