My place of work is fully air conditioned, doors can not be left open because of security issues, there are no windows.
Even before Corona, we (the staff) are regularly ill with sore throats, voice loss etc which we 'think' is down to the air conditioning. (One colleague lost her voice for 6 months last year).
... I'll leave the rest to everyone's imagination....
Yes, air conditioning has a lot to answer for.
The simplest form of air conditioning is a slender white box mounted on walls or ceilings, known as a split air conditioner, that draws in air from a room, chills it and then blows it back out again. This is no problem for a quick visit but there may be a risk over a period of hours as a study of a restaurant in China blamed this type of air conditioner for spreading coronavirus.
Many modern buildings where the windows are sealed have to rely on a ventilation system in which stale air is extracted from the rooms and piped to an air handling unit, often on the roof. There, fresh air can be pulled in from outside and mixed with the old inside air before being sent back into the building but often, in the interests of economy, not enough fresh air is introduced and this greatly increases the risk of coronavirus infection.
I am fortunate in that I can avoid air conditioned buildings and I don't think I've been in one since March.