Have you ever been there? If you want to talk about science, then define &quot;sick&quot; fisrt. For most people, frequently coughing would be considered as &quot;sick&quot;. Note that we are not discussing disease, we are talking about sickness, which I think is a less rigorous word sometimes referring to &quot;not feeling good&quot;.<p>I was born in Beijing and have been living there for more than two decades. And yes, I feel bad when I was exposed under that environment: I can hardly breathe, I coughed a lot and felt itchy in every inch of my skin. If you think that is not &quot;getting sick&quot;, then well, welcome to Beijing.