Mask use can be very dangerous to your health because of:
1) Reduced blood-oxygen levels leading to reduced mental clarity, lethargy, and reduced immunities. This condition, known as "hypoxia," can cause persons to lose focus and make bad decisions which can be dangerous to others. People are already falling asleep and fainting when doing routine tasks while wearing masks. The result could range from physical injury to self or others due to inattentiveness all the way to a social tragedy such as a rushed inaccurate verdict rendered by an oxygen-deprived masked jury that was unable to fully focus on and comprehend evidence and arguments in a case. The likelihood of viral infections increases with hypoxia because the body's natural defenses are degraded.
2) Carbon-dioxide toxicity from reduced ability of body to expel carbon dioxide (a waste product from all cellular activity).
3) Moisture retention in lungs due to the mask's retention of water vapor in the lungs. Moisture retention in lungs is a leading factor associated with pneumonia, bronchitis, viral and bacterial infections, asthma, and other respiratory ailments. Fluid build-up in the lungs can be very hard to treat and can result in death in serious cases of pneumonia and other ailments. If the lungs cannot take in dry air and expel humid air, then serious congestion may develop in the lungs.