The vigorous, exothermic decomposition of methyl ethyl ketone peroxide (MEKPO) can be stimulated by acids, metals, or heat, and the initial stage is critical to runaway reactions. Real-time thermal data are important in the evaluation of the hazards of fast reactions during the initial stage. We report the first real-time observation of the reaction of MEKPO with inorganic acids using a thermal imaging camera (TIC), which we used to determine the rate of heat evolution and to recognize the degree of the hazard present during accidents. In addition, ab initio computational methods were used to estimate the thermokinetic parameters for the proposed reaction mechanisms. The results indicated that the temperature of the solution, the concentration of the acid, and the dehydration ability were the primary factors that affected the thermal reaction. This work provides a new method to study thermal chemistry and to evaluate thermal hazards.