The stresses that evolve in a thermally shocked liquid were examined. The magnitude and time duration of stress transients generated by aQ‐switched ruby laser were measured in the absence of a phase change and compared with results calculated from a simplified thermodynamic model. It is shown that the model agrees with experimental data over a wide range of incident electromagnetic intensity and for large variations of liquid properties. Results are also presented to show the effect of liquid vaporization on the stress transients and the parameters associated with formation of a gas phase.