  Nanophotonics is an important branch of modern optics dealing with
light-matter interaction at the nanoscale. Nanoparticles can exhibit enhanced
light absorption under illumination by light, and they become nanoscale sources
of heat that can be precisely controlled and manipulated. For metal
nanoparticles, such effects have been studied in the framework of
$\textit{thermoplasmonics}$ which, similar to plasmonics itself, has a number
of limitations. Recently emerged $\textit{all-dielectric resonant
nanophotonics}$ is associated with optically-induced electric and magnetic Mie
resonances, and this field is developing very rapidly in the last decade. As a
result, thermoplasmonics is being replaced by $\textit{all-dielectric
thermonanophotonics}$ with many important applications such as photothermal
cancer therapy, drug and gene delivery, nanochemistry, and photothermal
imaging. This review paper aims to introduce this new field of non-plasmonic
nanophotonics and discuss associated thermally-induced processes at the
nanoscale.
