The risk of contracting COVID-19 mixed with sneezing droplets. People infected with COVID-19 Can be transmitted through droplets from sneezing, coughing, talking, etc., But the risk of getting people with COVID-19 floating in the air depending on location and humidity factors.

The risk of contracting COVID-19 Floating in the air will be more.  When you are in enclosed, crowded and poorly ventilated areas such as pubs, bars, restaurants, air-conditioned rooms. shopping mall supermarket Convenience stores with air conditioning, offices, classrooms with air conditioning, etc. If an infected person sneezes or coughs and then leave the droplets out of the secretions. People who are in the area at the same time. Including those who come to use the service later, are also at risk of contracting COVID-19. 

As said, small droplets It can mingle with the air for minutes to hours. In an enclosed space that is not ventilated no turnover. Especially in the air-conditioned room where the air is cold and humid. Those viruses and droplets last longer. Air currents from air conditioners can also carry the droplets contaminated with the virus to spread further.

weak person low immunity Having a congenital disease. There is a chance and risk of contracting COVID-19. that mix in the air a lot If entering those enclosed spaces. 

In the open area.  The air is circulated There is a current that can blow through. It reduces the concentration of aerosol secretions and viruses in the air. The risk of contracting COVID-19 therefore there are less.