BACKGROUND AND OBJECTIVES: Hypothermia contributes to neonatal mortality and morbidity, especially in preterm and low birth weight infants in developing countries. Plastic bags covering the trunk and extremities of very low birth weight infants reduces hypothermia. This technique has not been studied in larger infants or in many resourcelimited settings. The objective was to determine if placing preterm and low birth weight infants inside a plastic bag at birth maintains normothermia. METHODS: Infants at 26 to 36 weeks' gestational age and/or with a birth weight of 1000 to 2500 g born at the University Teaching Hospital in Lusaka, ZMB, were randomized by using a 1:1 allocation and parallel design to standard thermoregulation (blanket or radiant warmer) care or to standard thermoregulation care plus placement inside a plastic bag at birth. The primary outcome measure was axillary temperature in the World Health Organization-defined normal range (36.5-37.5°C) at 1 hour after birth. RESULTS: A total of 104 infants were randomized. At 1 hour after birth, infants randomized to plastic bag (n = 49) were more likely to have a temperature in the normal range as compared with infants in the standard thermoregulation care group (n = 55; 59.2% vs 32.7%; relative risk 1.81; 95% confidence interval 1.16-2.81; P = .007). The temperature at 1 hour after birth in the infants randomized to plastic bag was 36.5 ± 0.5°C compared with 36.1 ± 0.6°C in standard care infants (P < .001). Hyperthermia (>38.0°C) did not occur in any infant. CONCLUSIONS: Placement of preterm/low birth weight infants inside a plastic bag at birth compared with standard thermoregulation care reduced hypothermia without resulting in hyperthermia, and is a lowcost, low-technology tool for resource-limited settings. Pediatrics 2013;132:e128-e134. Copyright © 2013 by the American Academy of Pediatrics.