Energy balance

Brown adipose tissue (BAT) glucose uptake during cold exposure does not significantly contribute to systemic glucose clearance or thermogenesis because most taken-up glucose is metabolized into lactate or used for glyceroneogenesis rather than mitochondrial oxidation.

Cold exposure activates brown fat, but don't expect it to significantly lower your blood sugar or burn calories through glucose oxidation. The glucose taken up is mostly recycled into lactate or fat, not burned for heat. Focus on other mechanisms if targeting glucose metabolism.