The effect of temperature on the damage mechanisms occurring in a toughened acrylic resin was investigated by studying volume changes during tensile tests, analyzing the reversibility of the damage after applying proper thermal histories and by direct transmission electron microscope observations. It was found that an increase of temperature, from 0 degrees C to 60 degrees C, shifts the predominant mechanism from crazing to cavitation and shear yielding. When the latter occur, the material response is very susceptible to previous thermal treatments; and in particular to the cooling rate from above glass transition temperature. Crazing on the other hand is not influenced by the thermal history of the material. POLYM. ENG. SCI., 59:566-572, 2019. (c) 2018 Society of Plastics Engineers