Hydrogen-powered combustion systems are seen as a highly feasible option to decarbonise several industrial sectors including maritime, aircraft and power generation by and beyond 2050. It is therefore critical to understand if hydrogen-induced degradation, such as hydrogen embrittlement, could happen in high-temperature alloys used inside the combustion chamber. While H embrittlement is well documented in literature for near room-temperature applications, it is not clear how H interacts with high-temperature materials during H combustion. This work presents a systematic study of Inconel 718 exposed to different H-rich flame conditions to gain fundamental understanding of the conditions faced by Ni-base superalloys in hydrogen combustion engines. Inconel 718 samples following various heat treatments were exposed to a pure hydrogen flame between 400 °C and 750°C in fuel-rich conditions gaining deep insights into the dependence of exposure time vs hydrogen uptake, as well as the change in material properties due to H absorption. Following this, a relationship was established between combustion time and temperature vs total hydrogen content within the sample using thermal desorption analysis. Additional mechanical testing, via in-situ SEM tensile deformation, was carried out in selected conditions to characterise the deformation and damage mechanisms present and compare them against the existing mechanisms of H embrittlement in superalloys. Results of the study showed that a clear dependence exists between exposure time to hydrogen and H uptake in the sample. Additionally, it was observed that flame condition -as well as temperature- can substantially affect hydrogen absorption.  The study provided critical insight into the deleterious environmental effects of hydrogen combustion on nickel-base superalloys. By understanding the environment in which future engine materials operate, the transition to carbon-free transport and energy sectors can be significantly accelerated.