The motion of closed magnetic structures, plasmoids, in the solar atmosphere is examined in a simple model. A system of equations describing the dynamics, the internal energy balance, and the ionisation processes is solved numerically. While the plasmoids are accelerated and heated, ionisation and recombination processes of the ions take place. Depending on the initial conditions near the solar surface, various outcomes are possible. Coronal mass ejections (CMEs) usually show freezing-in temperatures of a few million degrees Kelvin, yet some rare observations of He + , indicators of a much lower freezing-in temperature, have been reported. Similarly, the model equations permit solutions with extreme charge state distributions. We discuss the results of the model calculations in relation to CME data registered by Ulysses, mainly from the SWICS instrument. Possible improvements of the model are discussed.