Wearing masks means we are breathing in more carbon dioxide

We breathe in oxygen and some of this carbon dioxide. When we exhale, we breathe out less oxygen but more carbon dioxide than we inhale.

If less oxygen is available to breathe, symptoms such as rapid breathing, rapid heart rate, clumsiness, emotional upsets and fatigue can result. As less oxygen becomes available, nausea and vomiting, collapse, convulsions, coma and death can occur.