Putting a 4-pound preterm baby in a warming box at 35 weeks gestation is likely to take about 1-2 weeks, depending on your doctor’s instructions. A 4 pound preterm baby is a mid-term fetus, and generally the younger the gestational age, the lower the weight, and the longer it will need to be kept in a warming box for treatment. The exact placement time varies, and may take about 1-2 weeks, but perhaps longer. The main observation of the baby’s development is that if the baby has a rosy color, can breathe on its own, eats normally, and does not vomit, then it can be taken out of the incubator. Preterm babies are transferred to the general ward after leaving the incubator and need to continue to be observed for 2-3 days. It is up to the doctor to make the judgment. In addition, preterm babies’ resistance is relatively weak, families must do a good job of nursing, and pay attention to small meals when feeding.