A premature infant needs a stable thermal environment. This paper studies if the infant weight can be employed in the standard heat regulation system in incubators. This was done in two stages. First, a weight sensor was designed by means of using strain gauge in order to provide weight measurement. Later, a heat regulation circuit was designed and implemented by means of using a microcontroller. The humidity, environmental and skin temperature, and infant's weight are measured and used as inputs. The experiments showed that infant's weight can be successfully added to the control circuit in the incubator instrument. The results showed that infant's weight can productively contribute in temperature control with good confidence. The average standard error was equal to 0.48 °C. The results reveal that the infant's weight can contribute to increase quality assurance of incubators.