Everyone knows how difficult it is to stay in an unventilated area for a long time: headache starts to ache from stuffiness, lethargy, weakness, drowsiness appear … Many people explain this by the lack of oxygen. And they are mistaken.
In the air of a poorly ventilated room, the oxygen content decreases so slightly that it can not have any negative effect on the body. Glory, for example, about the beautiful air of Kislovodsk spread throughout the world. And in this city. Continue reading