evidence: No. There have been false reports that face masks can lead to carbon dioxide poisoning (known as hypercapnia) from re-breathing the air we normally breathe out. But this is not true. Carbon dioxide molecules are very tiny, even smaller than respiratory droplets. They cannot be trapped by breathable materials like disposable masks. In fact, surgeons wear tight fitting masks all day as part of their jobs, without any harm. [...] Can masks lead to a weaker immune system by putting the body under stress? No. Wearing a face mask does not weaken your immune system or increase your chances of getting sick if exposed to the COVID-19 virus. Wearing a mask, even if you do not have symptoms of COVID-19, helps prevent the virus from spreading.