A solar flare releases a large amount of energy through magnetic reconnection, which forms hundreds of flare loops. These loops, difficult to be distinguished in the corona, can be resolved at their feet in the chromosphere with high-resolution imaging observations. To understand the properties of energy release in these individual events, in this study, we measure the chromosphere brightness at the foot-points of flare loops, and their rise and decay times. We have studied 18 flares observed by the Atmosphere Imaging Assembly in the past decade. We find that the individual heating events resolvable by AIA exhibit very similar temporal profiles characterized by an impulsive rise of < =2 minutes followed by a fast decay and then a slow decay. These quantities allow us to infer the amount of energy deposited in each flare loop and to examine the subsequent heating and cooling of plasma in the loop.