  We analyse the thermodynamic properties of a generalised Dicke model, i.e. a
collection of three-level systems interacting with two bosonic modes. We show
that at finite temperatures the system undergoes first-order phase transitions
only, which is in contrast to the zero-temperature case where a second-order
phase transition exist as well. We discuss the free energy and prominent
expectation values. The limit of vanishing temperature is discussed as well.
