Proposals to use a helmetlike interface for noninvasive positive pressure ventilation (NIV) can be traced back to more than a century ago. Among the earliest descriptions, Brauer and Petersen,1 in 1904, developed a helmetlike positive pressure ventilation “cabinet” to be placed around the patient’s head, with an air-tight seal formed via a soft neck collar. This prescient invention garnered little attention at the time. Instead, negative pressure ventilation via the “iron lung” gained widespread use to treat respiratory failure from polio and was superseded by endotracheal intubation for invasive mechanical ventilation by the 1960s. Although the physics of various mechanical ventilation devices is similar (pressure difference between airway opening and alveolus drives airflow), the interface used can have important implications for features of mechanical support possible, access of health care personnel to the patient, and comfort of the patient that may influence efficacy.