I've worked in one and I got used to it, wearing it for an hour at a time for 4-5 hours per day. For comfort, a positive pressure air purifying respirator (PAP

I've worked in one and I got used to it, wearing it for an hour at a time for 4-5 hours per day. For comfort, a positive pressure air purifying respirator (PAPR) is preferable but looks like you're on a biohazard scene.