<p>Here we
investigate for the first time the opto-thermal behavior of SiO<sub>2</sub>/Si
core/shell microbeads (Si-rex) irradiated with three common Raman laser sources
(lambda=532, 633, 785 nm) under real working conditions. We obtained an
experimental proof of the critical role played by bead size and aggregation in
heat and light management, demonstrating that in the case of strong
opto-thermal coupling the temperature can exceed that of the melting points of
both core and shell components. In addition, we also show that weakly coupled
beads can be utilized as stable substrates for plasmon-free SERS experiments.</p>