In the last couple of decades, non-thermal (“hot”) carriers in nanostructures have been simultaneously an inspirational concept to which a series of effects were ascribed, but also a source of confusion and hot debates. My talk will be aimed at describing the advances we obtained in the understanding of the role played by “hot” carriers in metals as well as transparent oxides via rigorous modelling of their generation process and dynamics, and extensive comparison to previous and new collaborative experimental work. [more]