Abstract: A method and apparatus for controlling the temperature inside an incubator. The incubator includes a heater for heating the air circulating therein. A temperature controller measures the skin temperature of an infant therein and at least one other temperature within the incubator environment which has a significant effect on the infant's skin temperature. The controller responds to the measured temperatures and other calculated temperatures to either turn on or turn off the incubator air heater so as to keep the temperature difference between the infant's skin and the environment, which affects skin temperature, below a preset maximum. The controller also causes the rate of temperature changes within the incubator to be minimized.