Brown adipose tissue (BAT) is considered as a potential therapeutic target against cardiometabolic diseases. Activated BAT combusts fatty acids leading to a reduction in fat fraction (FF). Both cold exposure and pharmacological stimuli can activate BAT, but the short-term dynamics of BAT activation are still unknown. To assess supraclavicular BAT (scBAT) FF dynamics during cold-exposure, we developed a 1-minute time resolution MRI protocol using breath-holds and co-registration to minimize motion-artefacts, and tested the protocol in five individuals. Co-registration resulted in low variation (<0.5%) and dynamic FF changes during cooling differed between subjects, possibly due to variable responses to thermoneutral conditions.