Abstract: A storage drum heater has an elongated housing and is typically used in a vertical orientation between storage drums arranged on a pallet. In one embodiment, the housing has closed ends and vertical sides that intersect four vertical, diagonal surfaces at their vertical edges. A column of holes is located in each diagonal surface, upper holes being axially spaced from lower holes. The housing contains a blower fan and a resistive heating element for heating air expelled by the blower. A battery is located in the housing and provides electrical power for operating the fan and the heating element. The fan draws air into the housing through the lower holes, then blows the air across the heating element and out of the housing through the upper holes, preferably into the V-shaped interstitial space between drums.