A new method of inducing crazing and cracking in thermoplastics is discussed. The method involves the thermal quenching of hot thermoplastics into simple organic liquids or organic solutions. Data are presented for several different thermoplastics and a number of different liquids. The results are interpreted in terms of a model based on the work of Manning and Lineback that incorporates thermal strains and stresses, thermal conductivity, specific interfacial energies, and defects. The specific crazing energy for bisphenol-A polycarbonate when quenched into isopropyl alcohol is determined to be approximately 3 X 10(5) erg/cm2 from this model.