Right well in that case it might make sense. I would not want to be wearing a full face respirator all day long.
Discussion
No it sucks... humidity build up inside the masks is the worst in the summer. I made a down draft sanding table so I can get away with a paper mask on most things, but MDF is a bitch. It is wood pulp with formaldehyde (☠️) as the binder, and the kicker is that when sanded or routed it gets electrically charged and wants to stick to you.