The prevalence of obesity and type 2 diabetes is at epidemic proportions. Classical interventions aimed at targeting obesity, such as reducing energy intake or increasing exercise, are often not effective over the long term. In contrast to white adipocytes, which store energy, brown adipocytes generate heat via mitochondrial uncoupling protein 1, thereby acting as a defence against hypothermia and, potentially, obesity. In this issue of Diabetologia, Admiraal et al compare brown adipose tissue activation during cold exposure between two different ethnic groups: South Asians and Europids. The prevalence of abdominal obesity and type 2 diabetes differs among various ethnic groups and decreased BAT metabolic activity could be one causal factor. As yet, the clinical impact of this 'rediscovered' organ is largely unknown, but has potential as a drug target for obesity.