Dubai: While face masks remain our best line of defence against COVID-19, health care specialists advise those with underlying heart conditions and respiratory disorders who are observing the fast and are in a labour-intensive industry to exercise special precautions to avoid any respiratory distress. The National Institute of Health (NIH) in the United States published a research paper earlier this year on this subject. Wearing a mask for long hours does not hamper any healthy person who is fasting. However, it can cause respiratory distress in those with cardio vascular diseases and respiratory diseases. People who are involved in industries such as hospitality and health care, who may be exposed to heat and thermal strain while wearing their personal protective equipment (PPE), have also been advised to observe caution.