Brown adipose tissue (BAT) has received enormous scientific and lay attention in the recent past as its thermogenic, energy‐consuming capacities represent prime candidates for therapeutic interventions toward obesity, glucose intolerance, and diabetes even in humans. The overall positive effects of BAT activation and recruitment on systemic energy homeostasis have been largely attributed to the inherent ability of brown adipocytes to combust fatty acid and glucose energy substrates through mitochondrial uncoupling, driven by the unique expression of uncoupling protein 1 (UCP1). Two recent reports by Boutant et al and Mahdaviani et al now identify the GTPase mitofusin (Mfn) 2 as a key determinant of BAT thermogenic function that is largely independent of its previously described role in mitochondrial fusion [1,2].