[en] The Master Curve (MC) methodology has evolved, from only being a brittle fracture testing and analysis procedure, to a technological tool capable of addressing many more structural integrity issues like constraint and parameter transferability. One issue that not yet has been covered by the MC is the warm pre-stress (WPS) effect. This effect, which is known to produce an effective increase in fracture toughness may be of great importance for some structural safety assessment situations, where thermal transients are involved. Here, the WPS effect is re-examined and implemented into the MC methodology. (orig.)