Id argue that the more obvious sign would be one in which all three drawings are present, but stacked vertically, with the radiation sign on top, followed by the death's head, but with an = sign between those two and no wavy arrow rays. Then below those two and their = sign, the person running with arrow. This would make it obvious that the radiation in the object means death and that running is extremely recommended. The triangle of graphics, with the radiation rays hitting both below almost seems to imply that X time is so deadly that you have no hope of escape even if you run.