Abstract: In an embodiment, a flexible fluid storage and warming bag may be provided. The flexible fluid storage and warming bag may include two flexible main walls, each including a surrounding edge, the two flexible main walls overlapping each other and being fluid-tightly sealed together along the surrounding edges thereof, the bag including a single non-partitioned fluid chamber defined by and between the two flexible main walls and by the sealed surrounding edges; at least one fluid transfer port extending into the single non-partitioned fluid chamber and being configured to allow transfer of the fluid into and out of the bag; and an electrical heating element integrated with at least one of the two flexible main walls of the bag. A fluid storage and warming system may also be provided.