Infrared thermography (IRT) has been applied in several areas of science. Particularly in the field of engineering, which has proven to be an excellent tool in non-destructive evaluations of structural components. In addition, IRT has also been applied to assess fatigue limits for structural materials from uniaxial cyclic stress tests or quasi-static uniaxial tensile tests. Recently, the quasi-static method to measure the fatigue limit via IRT was extended to biaxial stress states acting on the surface of real size pipeline specimens with dents. The results showed that the quasi-static biaxial method satisfactorily predicted the location of the hot spots for fatigue initiation in tubular specimens with dents. In this dissertation, the strain distributions at the critical points were determined from mechanical test using digital image correlation (DIC) applied to seven uniaxial standard dog bone and eight 3-meter-long pipeline specimens with plane headed caps fabricated from API 5L Grade B steel. The determination of the deformation state via DIC and the corresponding temperature variations for observed points on the material surface allowed to determine not only the material endurance limit, but also what may be called as the characteristic minimum temperature (TMC). Uniaxial tests using dog bone specimens for the same material indicate that the measured TMC are closely related to the material yield strength (MYS). This work brings originality in the definition and determination of the TMC point. In uniaxial tests the TMC point is determined through the temperature-strain-stress curves, while in biaxial tests, it is located in the temperature-pressure-strain curves.