Exploratory investigations were performed on the effect of stress concentrations upon the stresses generated in a free elastic plane space by thermal shock applied to the boundary. The emphasis was on a search for a general upper bound to the stresses induced in a plane space of arbitrary shape by a temperature change T0 applied to the boundary of the space. Theory indicates that, when a thermal shock penetrates into a plane elastic space a distance less than half the local boundary radius of curvature, then αET0 would be the magnitude of the upper bound and the stress field would be confined to a boundary layer. In order to obtain the reported results it was necessary to obtain temperature and fringe pattern data within 10 sec from initiation of thermal shock. The experimental program to accomplish this result is reported in detail.