  The recent Planck results and future releases on the horizon present a key
opportunity to address a fundamental question in inflationary cosmology of
whether primordial density perturbations have a quantum or thermal origin, i.e.
whether particle production may have significant effects during inflation. Warm
inflation provides a natural arena to address this issue, with interactions
between the scalar inflaton and other degrees of freedom leading to dissipative
entropy production and associated thermal fluctuations. In this context, we
present relations between CMB observables that can be directly tested against
observational data. In particular, we show that the presence of a thermal bath
warmer than the Hubble scale during inflation decreases the tensor-to-scalar
ratio with respect to the conventional prediction in supercooled inflation,
yielding $r< 8|n_t|$, where $n_t$ is the tensor spectral index. Focusing on
supersymmetric models at low temperatures, we determine consistency relations
between the observables characterizing the spectrum of adiabatic scalar and
tensor modes, both for generic potentials and particular canonical examples,
and which we compare with the WMAP and Planck results. Finally, we include the
possibility of producing the observed baryon asymmetry during inflation through
dissipative effects, thereby generating baryon isocurvature modes that can be
easily accommodated by the Planck data.
