OBJECTIVE: Newborns are prone to hypothermia immediately following birth. Hypothermia is associated with increased morbidity and mortality rates. We sought to assess the thermal environment and metabolic costs associated with exposure to various situations in the delivery room when skin-to-skin care (SSC) has to be curtailed. METHODS: Environmental variables (air temperature: T(a); relative humidity: RH; radiative temperature: T(r); and air convection velocity) were recorded during sequences reproducing SSC, in the maternity unit's various rooms ("passive environments") and in incubators ("active environments"). Analytical calorimetry was then used to calculate the body heat loss (BHL) from these data. RESULTS: The analysis of 1280 measurements of T(a,) RH, T(r), and air convection velocity in SSC, passive and active environments revealed that (i) the thermohygrometric environment during SSC was optimal (T(a): 32.7\,±\,3.2\,° C; RH: 50.9\,±\,5.6%), (ii) BHL rose when SSC had to be interrupted, and (iii) the use of a radiant incubator prevented hypothermia and reduced dry BHL but not humid BHL (9.4\,±\,1.5\,kcal/kg/h; p\,<\,.001), relative to SSC (5.8\,±\,2.0\,kcal/kg/h; p\,<\,.001). CONCLUSION: The newborn infant's thermohygrometric environment is optimal during SSC in the delivery room. When SSC was interrupted, T(a) and RH always decreased, and BHL increased in all passive environments.