There are now three types of adipose tissue, brown, beige (or brown in white) and white, which each have different tissue-specific molecular markers. Brown adipose tissue (BAT) is the least abundant fat in the body but is characterised as possessing uncoupling protein (UCP)1 which has the capacity to generate up to 300 times more heat than any other tissue (Symonds 2013). Adipose tissue is one of the last tissues to appear in the fetus, and BAT, in particular has the essential feature of enabling the newborn to effectively adapt to cool exposure of the extra-uterine environment (Symonds, et al. 2012c). Significant depots of BAT are present both around central organs such as the kidney and heart but BAT is also present in the 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 a current focus of academic debate (Pope, et al. 2014). These processes can be manipulated by environmental challenges to the fetus and/or neonate, offering the potential to promote BAT function in the newborn as well as into later life (Symonds, et al. 2010). Advances in our ability to understand tissue, or depot, specific roles of fat together with its impact on whole body energy regulation (Sacks and Symonds 2013) will be critical in developing effective early life strategies designed to prevent obesity. To this end, we have now 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 is much greater in children than adults and is negatively associated with body mass index (Robinson, et al. 2013; Robinson, et al. 2014). We are now beginning to further explore the impact of other factors on BAT function including diet and genetics (Symonds, et al. 2012b). These advances bring new opportunities to quantify, and manipulate, BAT development in early life, not only promote survival of the newborn but also to prevent excess adiposity through into later life (Symonds and Budge 2012).