A forced air warming unit has a casing with inlet and outlet openings. The casing encloses a scroll housing with a curved inside surface in which a blower is disposed. A circuit board in the casing encloses the blower in the scroll housing. At least one opening penetrates the circuit board. A heater plate is disposed between the circuit board and the blower. The blower draws air through the inlet opening, along a first side of the circuit board through the at least one opening into the scroll housing. The blower also forces air along a second side of the circuit board which faces the scroll housing, through air passages in the circuit board, along the first side through the at least one opening, into the scroll housing. The blower accelerates air along the curved inside surface and past the heater plate. Heated, pressurized air exits through the outlet opening.