BATokines as Biomarkers of Brown Fat in Humans

"A cold vest will be placed on the participant (consisting of a water-perfused CFA wearable vest, size S-M or M-L with adjustable straps Polar Products, Stow, OH; attached to a small 'cooler' reservoir to circulate cold water between the vest and the cooler; Product link: https://www.polarproducts.com/polarshop/pc/CoolOR-13-Quart-System-with-Arctic-Chiller-p24757.htm This product is safe and recommended by experimental guidelines and BARCIST criteria for human BAT studies. Note, the cooling vest will be cleaned between participants according to the manufacturer's guidelines found here: https://www.polarproducts.com/polarshop/pc/catalog/pdf/Polar\_CoolFlow\_Manual.pdf.~Briefly, the vest will be hand washed with a mild detergent and warm soapy water and air-dried. The vest will then be stored in a clean, dry environment with ventilation."

Participants will be requested to refrain from food and caloric drinks overnight (starting at 10pm) prior to the hospital visit. Blood will then be drawn the following morning (between 8 and 9am) and 3hrs later (between 11am and noon). Participants will be sat in a room with ambient temperature (room temperature w/o cooling) between the two blood draws.