This work explores the unsteady heat flux distribution on a high-pressure turbine vane subjected to periodic fluctuations in inlet total temperature, using computational fluid dynamics (CFD) simulations. The vane experiences sinusoidal fluctuations in temperature, with peak-to-peak amplitudes of 50 K over the investigated frequency range. Unsteady Reynolds-Averaged Navier-Stokes (URANS) simulations are conducted using the k-!SST transitional turbulence model, which accounts for turbulent production, dissipation, and convective heat transfer, thereby enabling the prediction of time-resolved stagnation effects on both velocity and thermal boundary layers. The computational model has been verified by comparing predicted pressure distributions and surface heat fluxes with experimental data obtained from a high-pressure turbine vane. The analysis focuses on the temporal development of near-wall velocity and temperature profiles over the oscillation cycle, highlighting the mechanisms driving the transient heat transfer response. Furthermore, spectral proper orthogonal decomposition is applied to identify the dominant flow and thermal structures controlling the unsteady momentum and heat transfer dynamics. Insights into the evolution of the thermal boundary layer provide guidance for improving flow management and cooling strategies, aiming to mitigate vane thermal loading while reducing coolant requirements.