In this work, we have investigated the thermal features of hydrogen peroxide-based energetic materials formulations. Initial research has shown that both the auxiliary oxidiser (sodium nitrate, potassium nitrate or calcium nitrate) and sensitising agent (glass microspheres) have significant influence on the rate of hydrogen peroxide decay in such formulations. In terms of the thermal features of the tested energetic materials, a similar and significant influence of the auxiliary oxidising agent and sensitising agent choice was observed. We have established that the use of calcium nitrate as an auxiliary oxidising agent (at ambient temperature of approx 20 °C), which allows the formulations to maintain capacity to undergo detonation for longer under storage conditions, negatively impacts the qualitative characteristics of the mixture as an energetic material. The thermal effects accompanying chemical interaction are much smaller than mixtures containing potassium and sodium nitrates as additional oxidising agents. Another important conclusion is that glass microspheres as sensitising agents significantly impact the thermal decomposition processes of the investigated on-site mixed (OSM) energetic material (EM) samples, except for the mixture using calcium nitrate.