DEVELOPMENT OF CIRCADIAN-RHYTHM OF HUMAN-BODY TEMPERATURE

Daily periodic body temperature changes were examined in 138 subjects aged 5 days-44 yr. The circadian rhythm of human body temperature was not discerned in newborn babies but body temperatures were higher in the daytime than during the night in infants over 1 mo. Temperature rhythm similar to that of adults with respect to phase was observed in the 10-11 mo. and over age groups, earlier than previously reported. The amplitude in circadian oscillation was, however, significantly larger in children from 7 mo.-7 yr old than in adults. Apparently, the adult type of circadian rhythm of human body temperature is fully established with respect to phase and amplitude after age 7 yr.