This patient isolation module has a transparent cubicle mounted over an hospital bed. This cubicle has a rectangular room-air intake opening at one end thereof, and an air treatment unit mounted outside the other end. The air treatment unit has fan inlet openings communicating inside the cubicle and forming a crown over the head of the bed. The air treatment unit draws air from the cubicle and causes a stream of fast-moving air to move along the cubicle, in a toe-to-head direction relative to a patient laying in the hospital bed. The air stream defines a hood-shaped envelope extending over and along both sides of the bed, to better separate a patient's breathing zone from health-care workers standing near that patient's bed.