It is quite remarkable that atoms (and molecules or ions) can actually be trapped near the solid surface of an atom chip, at distances of a few micrometers. Given typical shallow trapping potentials and the low kinetic temperatures of the atoms, this is a situation that is manifestly not in thermal equilibrium: an ultra-cold cloud at some ľK or below should simply evaporate out of its trap if it equilibrates with the chip components, no matter whether these are in a cryostat or at room temperature. The reason for the exquisite (meta)stability of atom chip traps is rooted in the quite slow exchange of heat between the trapped particles and their "hot" environment because the two are only weakly coupled. This is not only good news for a calculation of the relevant rates (of energy exchange and particle loss), on the one hand, because perturbation theory can be applied. It also turns out, on the other, that for typical atom chip settings the rates can be experimentally measured, in particular when metallic structures are involved. We review in this chapter the progress made within the last decade for calculating and detecting neutral atom­-surface interactions in atom chips. For completeness, we also discuss results obtained for charged particles in front of a solid surface, which are of relevance for ion chips (see Chapter 13).