  We investigate the chromospheric counterpart of small-scale coronal loops
constituting a coronal bright point (CBP) and its response to a photospheric
magnetic-flux increase accompanied by co-temporal CBP heating. We used
co-observations from the AIA and HMI/SDO, together with data from the Fast
Imaging Solar Spectrograph taken in the Halpha and Ca II 8542 lines. We used a
new multi-layer spectral inversion technique to derive the temporal variations
of the temperature of the Halpha loops (HLs). We find that the counterpart of
the CBP, as seen at chromospheric temperatures, is composed of a bundle of dark
elongated features named in this work Halpha loops, which constitute an
integral part of the CBP loop magnetic structure. An increase in the
photospheric magnetic flux due to flux emergence is accompanied by a rise of
the coronal emission of the CBP loops, that is a heating episode. We also
observe enhanced chromospheric activity associated with the occurrence of new
HLs and mottles. While the coronal emission and magnetic flux increases appear
to be co-temporal, the response of the Halpha counterpart of the CBP occurs
with a small delay of less than 3 min. A sharp temperature increase is found in
one of the HLs and in one of the CBP footpoints estimated at 46% and 55% with
respect to the pre-event values, also starting with a delay of less than 3~min
following the coronal heating episode. The low-lying CBP loop structure remains
non-potential for the entire observing period. The magnetic topological
analysis of the overlying corona reveals the presence of a coronal null point
at the beginning and towards the end of the heating episode. The delay in the
response of the chromospheric counterpart of the CBP suggests that the heating
may have occurred at coronal heights.
