A portable device is provided that is used to warm a mammography machine and which comprises a warmer and a holder for the warmer, the holder having a charging mechanism for charging the warmer. The warmer includes an enclosed heating element and power source. The heating element is precisely regulated to ensure that the sensitive imaging elements are not damaged by an over-temperature condition, while at the same time permitting a rapid heating of the warmer for high cycle use. The warmer warms surfaces of the mammography machine that contacts human skin.