Temperatures estimated from 29 April 1986 Landsat Thematic Mapper (TM) data for the fire at the Chernobyl nuclear power plant are reassessed and a new range of distribution and temperatures of the hottest visible material is suggested. The detected shortwavelength infrared thermal radiance is interpreted to come from sources at around 1130-1430 K. occupying about 0·05 per cent of each of four ground resolution cells.