(A) Newborn infants have large interscapular and peri-renal BAT depots. (B) In adults, smaller BAT depots are located in the cervical, supraclavicular, axillary, peri-aortic, paravertebral and suprarenal regions. The mapping of these depots in adults is largely based on glucose uptake measurements by 18F-FDG-PET/CT imaging, which shows increased glucose flux at colder temperatures (shown in figure) and on post-mortem resections. The molecular and functional nature of individual (putative) BAT depots remains unclear in humans. Also note that the amount of BAT is highly variable between individuals, but when active BAT is present, it has been shown to correlate with improved metabolism (not shown, discussed in text). Emerging advances in BAT imaging will likely confirm additional depots.