A bottle made of PET which can be filled with a hot, warm or cold liquid has a neck, a body and a closed bottom. The body has a peripheral groove for pressure relief capable of collapsing in a controlled manner under the bias of an externally applied vertical axial load. The structure of the groove is such that after collapsing the bottle will not be able to resume its original shape unless it is subjected to the application of another external force of sufficient strength in reverse direction with respect to the force which was applied to obtain the collapsed shape.