Latex-free nasal hoods with mask-in-mask design, to draw excess gas into vacuum, reducing ambient N2O. Clear outer mask appears foggy to show patient is breathing through nose. Soft inner mask creates desirable nasal/facial seal and seal can be seen through clear outer mask. Low profile expands clinical field of view, provides easier access to the mouth, and prevents patients from adjusting the mask. Single use: minimises cross-contamination and saves staff time.