[en] The experimentally observed scaling laws for the electron temperature (Tsub(eo)) and energy containment time (Tsub(Ec)) with ohmic heating are derived from the two conditions: (a) the predicted critical Tsub(eo) for loss of poloidal equilibrium and (b) the proportionality of the ion heat flux to the Pynting vector. Condition (b) is inferred from the large fraction of ohmic power shown to be transferred to the ions. (author)