A device and method for reducing heat loss in at least one region of a subject's body is described. The device includes a mask component, a heat releasing reservoir, and a conduit connecting the mask component to the heat releasing reservoir and creating an airflow path therethrough, wherein the heat releasing reservoir includes at least one air permeable region that is impermeable to condensed water. Heat loss is reduced by the subject positioning the mask over the mouth and/or nose, positioning the heat releasing reservoir over the region of the subject's body, and passing warmed air exhaled by the subject into the mask through the conduit and into the heat releasing reservoir, such that the warmed air passes through the heat releasing reservoir while retaining condensed water within the heat releasing reservoir, thereby increasing the temperature of the air surrounding the at least one region of the subject's body.