High Flow O2 via a heated humidified Nasal Cannula (HFNC) has been reported to be useful in a hypoxic respiratory failure resulting from pneumonia, asthma, congestive heart failure, and pulmonary embolism. Additionally, HFNC effectively delivers a high FiO2 during pre-oxygenation for intubation, DNR/Palliative Care situations, and during invasive procedures such as EGD. In this case based discussion, the speaker will discuss the evidence behind and actual set up of HFNC, as well as common uses in the ED.