Thermocouples were installed in a reaction well (below its microcentrifuge tube) at the bottom of the chamber containing the EPCM and in the exothermic reaction chamber for experiments performed to characterize the temperature profiles of the heaters. The temperature acquisition rate was 1 Hz. Initial experiments were focused on refining the dimensions of the heater, optimizing the quantity and quality of CaO and water, and testing EPCM formulations-with the goal of minimizing initial pre-heating time and variability during the specified incubation period. In the optimized device, 20 gm of CaO and 6.8 mL of water were added to the bottom chamber and mixed by rotary stirring for five strokes to initiate the heating and then the components were assembled as discussed above.