Taming complex fluids with thermal fields

External fields, thermal and electromagnetic, induce a range of non-equilibrium effects in complex fluids consisting of nanoparticle suspensions (Soret, Seebeck, Peltier effects), which can be exploited in energy conversion (thermoelectrics), analytical devices for detection of biomolecules, or nanoparticle transport and assembly. The combination of Non-Equilibrium multiscale simulations and theory has paved the way to explain the physical behaviour of complex fluids under external fields, showing that their response is much richer than previously predicted. I will discuss how simulation techniques can be used to obtain thermophysical properties relevant in energy conversion problems and to uncover novel non-equilibrium effects in complex fluids, associated to the coupling of internal degrees of freedom of molecules and colloids with thermal fields.