HBG2 and methemoglobinemia: We report a case of a 40-year-old male who presented to the emergency department with central cyanosis, altered mental status, and hypoxia that was refractory to supplemental oxygen following ingestion of an alkyl nitrite product called "Liquid Gold". Arterial blood gas and co-oximetry confirmed a diagnosis of severe methemoglobinemia with a methemoglobin (MetHb) level in excess of 30%.