Circadian Rhythmicity in Cold-induced Thermogenesis

As an intervention, a personalized cooling protocol will be used in order to activate BAT and induce non-shivering thermogenesis. During the cooling procedure, subjects will be exposed to mild cold (approx. 14°C) for 150 min. Since the onset temperature of shivering shows a high interindividual variation, we will use a personal cooling protocol to ensure maximum non-shivering EE (and thus an equal maximum activation of BAT). The right temperature will be determined via a subjective method, e.g. to ask the subject if he or she experiences shivering. The time needed to achieve the right temperature is approximately 30-60 minutes. Then, the stable cooling period of 90 min is started. During this time the subject will be asked every 15 minutes whether he is experiencing shivering. If so, temperature will be increased with 2-3°C so that shivering just stops.