Thermal management issues necessitate the use of fuel as a heat sink for gas turbine and liquid rocket engines. As interest in heated fuels increases, it is important to understand what occurs in the flow path of an injector under flashing conditions. This article describes a flow visualization study to characterize the flow of flashing methanol through two high aspect ratio slot orifice injectors of differing sizes. Flashing conditions inside the injector flow path were induced via a combination of heating and back pressure adjustments. Volume flow rate, pressure measurements, and temperature measurements were made that allowed the discharge characteristics, the level of super heat, and other parameters to be calculated and compared. To give a basis for comparison, the flashing results are compared to the flow through the injector under cavitating conditions. Cavitation and flashing are observed to follow similar trends. As such, they appear to be related phenomena, and this relationship is shown. Bubble formation under cavitating or flashing conditions is observed to attenuate the injector's discharge characteristics. High-speed videos of the flow field were also collected. Several flow regimes and flow structures, unique to these regimes, were observed. The results suggest a possible way to predict an injector's performance under flashing conditions without running heated fuel through the injector. These results may be applicable to real world injector design and testing.