Abstract: An insulated vent cap includes a cover member having a circumferential rim extending around corresponding circumferential edges of both a substantially rigid cover sheet and a substantially rigid base sheet, wherein the base sheet is spaced apart from, and below, the cover sheet, to thereby define a sealed, air-tight insulating void there-between. A spacer extends from the coversheet to the base sheet, whereby the cover and base sheets are maintained spaced apart to maintain the insulated void or space between the cover and base sheets irregardless of ambient temperatures external and internal to the vent on an enclosure to which the vent cap is mounted.