Suppose I am in a room or system with a lot of smoke and it is difficult to breathe. If I put a hand fan in front of my face, does the wind from the fan blow the smoke away from my face, making it a easier for me to breathe, or does it increase the intensity of the smoke and make it harder for me to breathe?
If I put a hand fan in front of my face, does the wind from the fan blow the smoke away from my face
Yes it does, but this also depends on how well ventilated the room is. I'm assuming that it's not at all from context.
or does it increase the intensity of the smoke and make it harder for me to breathe?
Since the room is not ventilated, and since the region behind the fan is of slightly lower pressure than the front, it could be the case that you are taking the smoke already in the room and blowing it back on your face.
But in terms of smoke "intensity", I would say that it would be less since the air from the fan would further break up the smoke particles and spread it out over a greater area.
I would guess that using a fan would be advantageous but to a slight degree.
If the smoke is due to your work environment, then you should most definitely ask for breathing masks.
Your question also mentions emergencies. The only situation that I can think of where smoke and an emergency come together is in the event of a fire. The first thing you should be concerned with is getting away ASAP. You should get as close to the ground as possible and make your way to an exit. Using a fan in this case is completely pointless and wastes valuable time. Being close to the ground is very advantageous as smoke density is lowest there. It is less hot since hot air rises and fire needs oxygen to combust.