Do you need to keep the windows open?
Open window policy. Government guidance for offices says to "increase ventilation by keeping doors and windows open where possible and running ventilation systems at all times" . Bringing in air from the outside helps dilute any aerosols in the room that may contain the virus. Closing windows, on the other hand, allows the virus to concentrate in the air.
Room temperature rules. The Workplace (Health, Safety and Welfare) Regulations 1992 lay down particular requirements for most aspects of the working environment. Regulation 7 deals specifically with the temperature in indoor workplaces and states that: "During working hours, the temperature in all workplaces inside buildings shall be reasonable." Guidance suggests a minimum of 16ºC, or 13ºC if employees are doing physical work.
Icy chill. In the summer leaving windows open was not an issue. But it's already creating problems as we enter the colder months. One school was in the press for keeping windows open but not letting the children wear coats. There are also reports that rail operators could recommend leaving the windows open. To make matters even more confusing, there is some evidence that cold air can make us more susceptible to the virus.
The German approach. So far, it isn't clear what the UK government's advice is. However, in Germany, where ventilation is being used as a central strategy to control the virus, experts have suggested to open windows every 15 to 20 minutes for five minutes during the autumn and three minutes in winter.