Time evolution of EM_T at different locations in the two flares. Panels (a) and (c): T_EM maps and selected locations. The yellow contours in (c) show the locations of the AIA pixels that have counts greater than 15,000 DN in the 193 Å channel, a level very close to the saturation of the AIA detectors. Panels (b) and (d): time evolutions of EM_T. These plots directly show the plasma heating and cooling at different flare sites.