The precise estimation of surface heat flux and its quantification holds importance, particularly in applications of aerodynamic testing for hypersonic flights. The accuracy of measured heat flux is critical for hypersonic shock tunnel experiments that heavily rely on fast response thermal sensors. In this manuscript, the ability of an in-house developed coaxial thermal probe (CTP) is demonstrated through calibration experiments with real-time testing in a highly impulsive environment (shock tube). The CTP is made in-house using two thermo-elements, namely, chromel and constantan (3.25 mm diameter and 8.5 mm length), arranged coaxially and bonded together with a thin layer of epoxy. Calibration activities follow the fabrication process to determine CTP’s characteristics features (such as sensitivity and thermal product). The measurement through CTP is verified in a typical challenging environment using a shock tube that produces flow having higher magnitude of density, pressure, and enthalpy. The heat flux values, derived from temperature signals, exhibit a close match for both analytical and numerical methods. Numerical simulations also confirm a similar trend and magnitude with an uncertainty band of ±1.75%. The comprehensive investigation conducted in a shock tube provides assurance regarding the capability and dependability of the CTP.