Vomiting within the first hour, especially if accompanied by explosive diarrhea, is associated with doses that frequently prove fatal. Due to the transient nature of these symptoms, it is possible that the patient will have already passed through, this initial phase of gastrointestinal distress before being seen by a physician. It will be necessary to inquire about these symptoms at the initial examination. Casualties who have received a potentially lethal radiation injury show a significant rise in body temperature within the first few hours postexposure. Although our experience is limited, this appears to be a consistent finding The occurrence of fever and chills within the first day postexposure is associated with a severe and life-threatening radiation dose.
Present evidence indicates that hyperthermia is frequently overlooked.
This is also true for those who receive a comparable dose to a local body region in which case the erythema will be restricted to the affected area. A noticeable and sometimes clinically significant decline in systemic blood pressure has been recorded in victims who received a supralethal whole-body radiation dose. A severe hypotensive episode has been observed in one person who had received several thousand rads. Severe hypotension after irradiation is associated with a poor prognosis. Experience indicates that almost all persons who demonstrate obvious signs of CNS injury within the first hour postexposure have received a supralethal dose.