ObjectiveHypothermia on admission to the neonatal intensive care unit (NICU) is associated with an increased risk of death in preterm infants. There are currently no evidence-based recommendations for thermal care before cord clamping (CC). We wished to determine whether placing very preterm infants in a polyethylene bag (PB) before CC, compared with after CC, results in more infants with a temperature in the normal range on NICU admission.DesignRandomised controlled trial.SettingTertiary maternity hospital.PatientsInborn infants<32 weeks’ gestational age (GA).InterventionsInfants were randomly assigned to have a PB placed before or after CC.Main outcomeRectal temperature within the normal range (36.5°C–37.5°C) on NICU admission.ResultsBetween July 2020 and September 2022, 198/220 (90%) eligible infants were enrolled in this study; 99 (44 (44%) girls) were randomly assigned to BEFORE and 99 (53 (54%) girls) to AFTER. Median (IQR) GA 29 (27–31) vs 29 (27–31) weeks, mean (SD) birth weight 1206 (429) vs 1138 (419) g, respectively. The proportion of infants who had normal temperature on NICU admission did not differ between the groups (BEFORE 54/99 (55%) vs AFTER 55/98 (56%), p 0.824). The proportion of infants with a temperature outside of the normal range was similar between the groups; hypothermia (BEFORE 34/99 (34%) vs AFTER 33/98 (34%), hyperthermia (BEFORE 10/99 (10%) vs AFTER 10/98 (10%)).ConclusionsPlacing a PB before CC did not increase the proportion of preterm infants with normal temperature on NICU admission. A large proportion of preterm infants had abnormal temperature. Further studies on thermoregulation before CC are needed.Trial registration numberNCT04463511