  A general fluctuational-electrodynamic theory is developed to investigate
radiative heat exchanges between objects which are assumed small compared with
their thermal wavelength (dipolar approximation) in N-body systems immersed in
a thermal bath. This theoretical framework is applied to study the dynamic of
heating/cooling of three-body systems. We show that many-body interactions
allow to tailor the temperature field distribution and to drastically change
the time scale of thermal relaxation processes.
