  The Interface Region Imaging Spectrograph (IRIS) has observed bright spots at
the transition region footpoints associated with heating in the overlying
loops, as observed by coronal imagers. Some of these brightenings show
significant blueshifts in the Si iv line at 1402.77 A (logT[K] = 4.9). Such
blueshifts cannot be reproduced by coronal loop models assuming heating by
thermal conduction only, but are consistent with electron beam heating,
highlighting for the first time the possible importance of non-thermal
electrons in the heating of non-flaring active regions. Here we report on the
coronal counterparts of these brightenings observed in the hot channels of the
Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory. We
show that the IRIS bright spots are the footpoints of very hot and transient
coronal loops which clearly experience strong magnetic interactions and
rearrangements, thus confirming the impulsive nature of the heating and
providing important constraints for their physical interpretation.
