Why I open my mouth when I climb down steps

I open my mouth when I climb down steps for love of stove tiles!
For a week now I've been taking photos and measuring the stove tiles from the deposits of the museum. The deposit is in the basement and the dust, supplemented by fungi, has determined me to masquerade and wear gloves and a mask. But his mask, I don't know how surgeons can stand it, is very uncomfortable. It often moves and ends up covering my cheek and eyes, so whenever I walk down the stairs after taking photos of the tiles in natural light, I have to open my mouth in order to re-arrange the mask and see my steps. and since I do that some 40 times a day, I am honestly afraid of not developing a Pavlovian connection between the two actions.
And if you still wonder why I am doing all this, take a look at the tiles.