A mumbling homeless woman was left out in deadly near-zero temperatures on a Manhattan sidewalk overnight — with first responders telling The Post they couldn’t help her under city guidelines. The unidentified woman was wearing a hooded sweatshirt, slippers and two blankets as she clipped her nails, put lotion on her hands and talked to herself while hunkered down on East 34th Street across from NYU Langone Hospital as temperatures neared 0 degrees early Sunday.