And saw a diagram the other day of how, in a restaurant setting, covid was spread to socially distanced people via the ventilation system as there was more in the air than previously thought. That doesn't bode well for opening windows does it - you will be letting the virus in.
Was the restaurant ventilation system re-circulating air?
Opening a window at home is letting different air in from outside (I won't say "fresh air" as it depends where the home is situated), it's not letting the virus in. You might get a chill from sitting near an open window but you won't catch a virus.
All windows on a bus were open. I spent 40 minutes huddled-up against the draught on a cold, windy December day. I had to balance risks of being cold, inhaling traffic fumes through my mask, and Covid. The bus journey was necessary, returning from a hospital visit. Total number of passengers was 6. My area was in Tier 4 then. Came out of Tier 4 on 11th December and will return to it on Boxing Day.
Jason Leitch, Scotland's medical guru warned ages ago that Christmas wouldn't be normal. Nicola Sturgeon told us a week ago to limit visits to 1 day at Christmas. She said she intended to meet her parents for a walk but wouldn't be having Christmas dinner with them.