Spatially localized heat flux due to the locked mode in a reversed-held pinch device, TPE-RX, is investigated by using a multipoint vessel temperature monitoring system (VTMS) which has 268 thermocouples distributed on the outer surface of the vessel system. It is shown by two-dimensional mapping that the locally enhanced thermal wall load correlates closely with the mode locking positions. Heat flux shows spatial peaks (full width at half maximum) of similar to 10 degrees and similar to 100 degrees in the toroidal and poloidal directions. respectively. Typical heat flux at the locked position is estimated to be of the order of 100 MW/m(2), and the increment of the vessel temperature on the plasma side-surface exceeds 1000 degrees with 0.35 MA plasma current. (C) 2001 Elsevier Science B.V. All rights reserved.