An electric heating mat may include an outer sleeve having an interior, and an access end with an opening to the interior. The access end may be folded upon itself into a closed condition, and unfolded into an opened condition. When the access end is closed, the interior of the outer sleeve may provide a sealed enclosure. The sealed enclosure may accommodate and protect internal components, such as heating elements, a power source, and associated controls. The heating elements, associated wiring, and an insulation layer may be provided in an inner sleeve, which may be insertable into the outer sleeve as a unit. When the access end is opened, the opening provides access to the internal components. Such access allows the power source to be turned on to supply power to the heating elements.