  Ideas borrowed from renormalization group are applied to warm inflation to
characterize the inflationary epoch in terms of flows away from the de Sitter
regime. In this framework different models of inflation fall into universality
classes. Furthermore, for warm inflation this approach also helps to
characterise when inflation can smoothly end into the radiation dominated
regime. Warm inflation has a second functional dependence compared to cold
inflation due to dissipation, yet despite this feature, it is shown that the
universality classes defined for cold inflation can be consistently extended to
warm inflation.
