My associates and I had the unusual opportunity of studying a patient who had been subjected to severe freezing conditions. We believe this case to be unique insofar as the degree of hypothermia was more profound than is ordinarily followed by recovery in the human or in most animals.1The critical level in humans is unknown, but it is commonly considered to be between 68 and 74 F.2Although some nonhibernating experimental animals have recovered from more profound hypothermia than did this patient, their periods of hypothermia were considerably shorter.3 CASE REPORT At 8 a. m., Feb. 8, 1951, a Negro woman, 23, was brought into the admitting room of Michael Reese Hospital. She had been found by policemen about 15 minutes previously in a nearby alley in a frozen coma. The policemen assumed that she was dead because they were unable to detect any apparent respirations.