Please help with Body Prep / Engine Bay

I am doing the same process... I have done the drivers side and trunk area all by hand sanding... I had to go all the way to metal due to the 4 layers of paint on top of the original paint... but I was wondering what is the safest way to do around the front end and engine compartment (just outside of the car, the engine bay can wait a little while) and outside air vents without removing the engine. I don't want the /6 to choke and I don't want to choke on paint particles and fumes either.