Respirators - don't do it, please
Please don't assume that if you put on a respirator that you are protected. First of all you need to have the correct cartidges for the work you are doing, and depending on the paint, you could need voc cartidges or some other chemical protectant cartridges. Second, respirators need to be fit tested to make sure you have the proper seal, otherwise they are useless. Third - wearing a respirator removes one of the bodies ways to remove excess heat. Do you know that breathing out is one of the MAJOR ways to remove heat from your body? As a person who has taught personal protective equipment for several years of my life my advice is-DON'T DO IT. Especially if you are not already accustomed to it. Any type of personal protective equipment has the ability to add extra stress to your body, and is something that you should probably avoid.
In my non-medical, but safety professional opinion, the respirator could be more harmful to you than latex paint fumes, and unless properly fit tested and outfitted will only give you a false sense of protection.
sorry for the rant, but this worried me.
LynnO