(Actually, on a theropod that big, feathers wouldn't be as insulating relative to the volume/surface-area gains due to increased size from the little theropods most likely to have feathers. And there's the issue of closeness of relationship to the avian ancestor line itself to consider-tyrannosaurid likely, allosaurid not so much. So it would likely be feathers on youngsters and for display if at all on grown individuals, and then most likely if that dinosaur is a tyrannosaurid. I must now go check if the painting included the arms.)