If you cant wear a mask for your own selfish reasons.

[Thulian]

helmets protect your head, they work
seat belts keep you attached to a vehicle, they work
dunno what a fighting ensemble is maybe you wear it during anal sex
gas masks help gas from going in your lungs
parachutes slow you down when you jump out of a plane
sterile tools prevent infection
body armor ? i only wear it in everquest

as for masks

they dont do anything