Both K-shell x-ray emission spectroscopy and fluorescence spectroscopy are well-accepted diagnostics for experimental studies of warm dense matter and hot dense matter (HDM). Until now, however, this diagnosis has been used for the study of dense matter with temperatures lower than 100 eV or with temperatures above 1 keV. In this work, we have demonstrated the possibility of using K-shell emission spectroscopy for an intermediate temperature range of 100s eV to study dense plasma. Here, we discuss an analysis of the HDM emission spectra of a solid-state copper with temperatures up to a few hundreds of electronvolts heated by laser-accelerated charged particles.