What action should a nurse take to reduce the risk of cold stress in a low-birth-weight newborn with a body temperature of 97.7°F (36.5°C)?

To reduce the risk of cold stress in a low-birth-weight newborn, applying warmed blankets that have been stored in a warmer is crucial. Newborns, especially those with low birth weight, are particularly susceptible to hypothermia due to their larger body surface area relative to their weight, which can lead to rapid heat loss.

Warmed blankets provide immediate thermal support, helping to elevate the newborn’s body temperature and prevent further heat loss. The use of heated blankets is a standard nursing practice aimed at maintaining normothermia in vulnerable infants. By ensuring that these blankets are warmed and readily available, the nurse creates a stable environment for the newborn's thermal regulation.

Other methods, such as keeping disposable diapers under warming lights, may not provide adequate coverage or warmth needed for the entire body and are not as effective as direct application of warmed blankets. Maintaining a low-humidity atmosphere can actually exacerbate heat loss, as low humidity can lead to increased evaporative cooling. Humidified oxygen via a hood is essential for some respiratory support but does not directly address the issue of maintaining body temperature. Thus, applying warmed blankets is the most effective and immediate intervention for managing the risk of cold stress in this scenario.