In theory, adjusting indoor environments—particularly temperature and relative humidity—could help slow the spread of pathogens like COVID-19 because viruses thrive more in certain conditions.
There have been few studies on this topic, and none specifically on the coronavirus wreaking havoc around the globe, though. Certain viruses prefer high relative humidity, while others including COVID-19, favor low humidity.
There is scant data to determine whether modifying indoor environments would do any good to slow the spread of viral pathogens. Indoor relative humidity may affect how long the virus remains suspended in the air or is viable, but probably not very significantly, according to a retired pulmonary physician.
Further research could find that temperature and relative humidity can have an impact so that the building code could recommend specific environmental conditions to reduce airborne infection risk.