We employ the concept of a dynamical, activity order parameter to study the
Ising model in a transverse magnetic field coupled to a Markovian bath. For a
certain range of values of the spin-spin coupling, magnetic field and
dissipation rate, we identify a first order dynamical phase transition between
active and inactive {\em dynamical phases}. We demonstrate that dynamical
phase-coexistence becomes manifest in an intermittent behavior of the bath
quanta emission. Moreover, we establish the connection between the dynamical
order parameter that quantifies the activity, and the longitudinal
magnetization that serves as static order parameter. The system we consider can
be implemented in current experiments with Rydberg atoms and trapped ions