Early Life Nutrition Research Unit, Academic Division of Child Health, School of Clinical Sciences, Queens Medical Centre, University Hospitals, The University of Nottingham, Nottingham, NG7 2UH, United Kingdom In precocial newborns such as sheep and humans, the onset of non-shivering thermogenesis through activation of the BAT specific uncoupling protein (UCP)1 is essential for effective adaptation to cold exposure of the extra-uterine environment (Symonds, et al. 2012c). For both species, significant depots of BAT are present both around central organs, such as the kidney and heart, but also around the neck or supraclavicular region. The extent to which these BAT depots are replaced by white adipose tissue, or are transformed to a mix of beige and white adipocytes, remains to be fully established. Over the first month of life in the sheep, the majority of the BAT depots laid down in the fetus undergo rapid depot-specific transition adopting white or beige characteristics. This process can be manipulated by environmental challenges to the fetus and/or neonate which, therefore, offer the potential to promote BAT function (Symonds, et al. 2010). We have developed the technique of thermal imaging in order to quantify potential changes in BAT activity through the life cycle in free-living subjects (Symonds, et al. 2012a). This has shown that BAT activity can be much greater in children than adults and is negatively correlated to body mass index. We are now beginning to further explore the impact of other modulators of BAT function including diet and genetic factors (Symonds, et al. 2012b). There is now a new opportunity to quantify and manipulate BAT development in early life in order to both promote survival of the newborn and also to prevent excess adiposity in later life (Symonds and Budge 2012).