@regen99 I cannot answer about steam cleaning the carpets - we use hot-water extraction & have a home machine that I can use, though I usually leave that to my husband. Actually, he cleaned our little patches of carpet - stairs, one hallway and a lower level family room, last night. He vacuums thoroughly after it dries with a HEPA filtered vacuum.
As for steam cleaning, we steam clean the hardwood, tile & stone (which is most of our house) with a steam mop and distilled water and have done for years. The stone is a bit hard on the mop heads, but I just buy replacements on line. The amount of steam produced is minimal, and I figure by the time it reaches head-level it is well dispersed. I have looked for a larger steam unit, which I assume would take less time, but all of them have a separate tank & wand and use tap water, which is a problem where we live due to minerals and would be a storage nightmare in our small home.
I have always felt the tradeoff between clean (steam is a good sanitizer if you go over each section 5-6 times) and potential low exposure to steam was worthwhile.
In an ideal world, I would hire this done, and be out of the house for that day, but this way it is done frequently and to our standards.