  Hot dust-obscured galaxies (Hot DOGs) are a population of hyperluminous,
heavily obscured quasars discovered by the \emph{Wide-field Infrared Survey
Explorer} (\emph{WISE}) all-sky survey at high redshift. Observations suggested
the growth of these galaxies may be driven by mergers. Previous environmental
studies have statistically shown Hot DOGs may reside in dense regions. Here we
use the Very Large Telescope (VLT) narrowband and broadband imaging to search
for Ly$\alpha$ emitters (LAEs) in the 6.8' * 6.8' field of the Hot DOG
W2246$-$0526 at $z=4.6$. W2246$-$0526 is the most distant Hot DOG. We find that
there is an overdensity of LAEs in W2246$-$0526 field compared with the blank
fields. This is the direct evidence that this most distant Hot DOG is in an
overdense environment on the Mpc scale, and the result relates to the merger
origin of Hot DOGs.
