  Cosmological phase transitions are predicted by Particle Physics models, and
have a variety of important cosmological consequences, which depend strongly on
the dynamics of the transition. In this work we investigate in detail the
general features of the development of a first-order phase transition. We find
thermodynamical constraints on some quantities that determine the dynamics,
namely, the latent heat, the radiation energy density and the false-vacuum
energy density. Using a simple model with a Higgs field, we study numerically
the amount and duration of supercooling and the subsequent reheating and phase
coexistence. We analyze the dependence of the dynamics on the different
parameters of the model, namely, the energy scale, the number of degrees of
freedom and the couplings of the scalar field with bosons and fermions. We also
inspect the implications for the cosmological outcomes of the phase transition.
