The Oxygen Cost of Minor Changes in Heat Balance of Small Newborn Infants

Summary Measurements of gaseous metabolism small newborn infants whose anterior abdominal skin temperatures were stabilized at fixed levels (35, 36 and 37°C) for 15 to 25 hours revealed that mean oxygen consumption was lowest in the 36°C condition. From the oxygen cost of small departures in heat balance it is suggested that a “neutral thermal state” small neonates may be achieved when environmental conditions are adjusted to maintain the abdominal skin temperature between 36 and 37°C. The deep body temperature in the “neutral thermal state” is lower in these very small babies than is generally considered to be a normal deep body temperature in human subjects. The relationship between temperature and metabolism in undergrown as compared with normally grown infants should be investigated further.