• Hypothermia in infants is associated with considerable morbidity and mortality. Infection is thought to occur frequently and to carry a poor prognosis in infants with hypothermia. The medical records of 51 infants less than 3 months of age hospitalized from 1976 through 1981 with rectal temperatures of 34 °C or less were reviewed. Infections were diagnosed in 27 of the 51 infants. infections were associated significantly with the presence of bradycardia, anemia, abnormal leukocyte counts, abnormal serum glucose levels, and uremia, especially if two or more of these variables were present. Morbidity and mortality were higher among infected than among noninfected Infants. No rapid reliable indicators for the presence or absence of infection in an individual infant with hypothermia were found despite the differences noted between the two groups. Until new techniques for the detection of bacterial infections became available, we suggest that antibiotics be given to all infants younger than 3 months of age with hypothermia on admission to the hospital.