I have been finding these masks all over the place. I try to put them on my head but they just fall on the floor (sometimes they fall through the floor and vanish). Either way Id like to know the importance of them since I am coming across a lot of them in places that seem like hidden loot spots. The way you hold the hat suggests that it is possible to put it on your head, but I have tried to perform the obvious actions to get my character to wear it, but it doesn't do anything.
As a follow-up question. What is the point of the masks, do they give some sort of health bonus when you put them on?
Yes, it is possible to put hats on. The mechanic and purpose of them is fairly useless though. It is almost 100% likely that you cant put the mask on because you are already wearing one. The game does a pretty terrible job at letting you know that you are wearing one. This begs the obvious question, what are the masks in Arazona Sunshine for? They are just for looks. If you are playing solo then they are absolutely useless as you can never see the mask you wear.
To take off the mask you are wearing, put your hand up to your face, press the hold button and you should be able to take the mask or hat away from your head.