Abstract: A blood heating apparatus, comprising a box provided with a hinged door with pins for suspending thereon a plastics pouch having a labyrinth-shaped passage communicating with flexible inlet and outlet tubes, said box and door are provided with temperature-controlled electrical heating assemblies to be contacted with both sides of said pouch and with passages for the tubes of said pouch. The door is hinged at its lower side on a horizontal hinge axis, and is provided with said suspension pins, the inlet and outlet tubes of said pouch communicating with said pouch symmetrically at two opposite sides being mutually aligned, the passages for said tubes in the box and door walls being situated in the vicinity of the hinge axis of said door.