What is the primary mode of heat loss for preterm infants in their first week of life?

The primary mode of heat loss for preterm infants in their first week of life is evaporation. Preterm infants have a significantly higher surface area-to-volume ratio, which contributes to greater fluid loss. Immediately after birth, when these infants are exposed to a cooler environment, evaporation occurs as moisture on the skin surface is converted to vapor. This process requires energy in the form of heat, which leads to a critical decrease in body temperature.

In a clinical context, it is essential to mitigate evaporative heat loss by using methods such as maintaining a warm, humidified environment and covering the infant with warm blankets. Understanding that preterm infants are particularly vulnerable to this type of heat loss emphasizes the importance of careful temperature regulation in the neonatal intensive care setting to prevent hypothermia and associated complications.