In the open air on a grassland, covid won’t kill a population. The design of our hermetically sealed buildings is what’s killing us.
Back in the 1970s the air outside was full of lead and smog, so the safest thing too was completely seal all office buildings.
Today the air inside probably contains more hydrocarbons (from volatile organic compounds offgassing from carpets and furniture) so the best thing to do is vent air to the outside and keep the windows open (assuming you live in a mild climate)
Of course, that flies in the face of all efforts to make things green…which involve better insulation, sealing windows against leaks, more air filtration systems and etc.
Here in Canada the temperature drops like 5 or 10 degrees when you walk into a forest. I’ve stepped into a traditional mud hut and experienced a similar cooling effect. The common denominator is that both environments have a high surface area compared to say concrete. This acts as an efficient radiator so that when water to evaporates it removes heat. In low humidity climates this is one way to reduce cooling demands. Beyond that if we cool micro zones or interstate cooling into clothing itself through hoses or something that might be the next step in efficiency…until it gives birth to the next problem.