Temperature Regulation
Thermoregulation is the ability to balance heat production and heat loss to maintain a neutral thermal zone. The aim is to maximize metabolic efficiency, decrease oxygen need and conserve energy for other basic functions. Newborns, especially preterm babies, are more at risk for hypothermia due to the large surface area to body mass ratio, decreased subcutaneous fat, poorly developed mechanisms f
Thermoregulation is the ability to balance heat production and heat loss to maintain a neutral thermal zone. The aim is to maximize metabolic efficiency, decrease oxygen need and conserve energy for other basic functions. Newborns, especially preterm babies, are more at risk for hypothermia due to the large surface area to body mass ratio, decreased subcutaneous fat, poorly developed mechanisms for heat production and immature skin leading to more insensible water and heat loss. The abdominal temperature should be maintained in the 36-37oC range, axillary temperature should be 36.5-37.5oC. Hypothermia predisposes babies to hypoxia, sepsis, hypoglycemia, apnoea and poor weight gain.
Put the radiant warmer on ‘prewarm setting’ and warm linen before the delivery of a baby. Dry term babies in theatre or labour ward and remove wet linen. Most heat loss occurs via the scalp therefore use woolen caps. Consider using a plastic bag as a blanket to conserve heat and moisture in VLBW infants. In stable term babies skin-to-skin contact with the mother is an effective method of temperature control in the delivery room. Transport babies in a prewarmed incubator and always check temperature before and after transporting the baby.
If using a radiant warmer for procedures or resuscitation make sure the temperature probe is attached to the baby’s abdomen and the servo-controlled mode is selected with the temperature set appropriately. Heat loss occurs through evaporation, radiation, convection and conduction. Ensure that doors are closed to prevent draughts. During daily checks nurses and doctors should check babies’ temperatures and adjust the incubator temperature appropriately.
The incubator thermo-neutral zone for a particular baby depends on his/her weight and postnatal age as per the table.
See table below for guidance on maintaining an ideal thermo-neutral status
| Age | Weight | Incubator Temp Setting |
| <24 hour | <1.2kg | 35 °C |
| 1.2-1.5 | 34 °C | |
| 1.5-2.5 | 33 °C | |
| >2.5 | 32 °C | |
| Day 1-4 | <1.2kg | 34 °C |
| 1.2-1.5 | 33 °C | |
| 1.5-2.5 | 32 °C | |
| >2.5 | 32 °C | |
| Day 4-12 | <1.5 | 33 °C |
| 1.5-2.5 | 32 °C | |
| >2.5 | 30 °C | |
| Day 12 - 1 Month | <1.5 | 33 °C |
| 1 Month - 6 Weeks | <1.5 | 32 °C |
| >6 Weeks | <1.5 | 31 °C |
Rahima Moosa Mother and Child Hospital - Neonatal Care Handbook 2023; Temperature regulation
Last checked for updates: January 2024