  Vitreous GeO$_2$ has been compressed at high temperature, to investigate the
effect of thermal activation on the structural reorganization during
compression. The measurements were performed in-situ using micro Raman
spectroscopy under pressure up to 6 GPa and temperature up to 400$^\circ$C. The
evolution of the Raman shift of the main band (400-500 cm$^{-1}$) with
temperature during compression evidences a pressure window around 3 GPa within
which temperature has a remarkable influence on the structure, in particular
the intermediate range order. We find that this change is well correlated with
previous ex-situ density measurements from high pressure-high temperature
densifications. Moreover, coordination changes from tetrahedrally (GeO$_4$) to
octahedrally (GeO$_6$) coordinated GeO$_2$ are accelerated with the heating
during the compression.
