Electron temperature and density profiles are measured by Thomson scattering of ruby laser light in a low-q DIVA plasma; the profiles are strongly affected by internal disruption. The effective electron conduction coefficients χep at the moment of internal disruption are calculated on the basis of the diffusion equation. – The average value of χep outside the q = 1 singular surface rD, 7.2 × 104cm2·s−1 is much larger than that expected for the base discharge, which implies that the internal disruption substantially enhances the thermal transport throughout the region rD<r⩽a. The χep(r) profile inside the q = 1 surface is approximated by the equation χep(r)= 1.4 × 105 × (1–(r/11)1.5)cm2·s−1 at 0⩽r⩽rD.