The basis of the simple,crude yet elegant solution worked out by British Motor Corporation (remember them?)
collector round exhaust manifold with duct to air cleaner INLET
Cold outside air ducted to cleaner inlet a pad is affixed to a substantial folded bimetal strip such that the pad is normally close to, or blocking the hot air duct. (think a pair of sugar tongs, one tong anchored, the other carrying the pad.....the "loop" faces TOWARD the air-cleaner which feeds the carb.(whole assembly is inside the duct and thus subject to induction-airflow)
Upon initial startup, the cold induction air passes over the bimetal , which pulls the pad away from the heated-air inlet...as the exhaust-manifold heats up, the warm air is blended with the cold air and this passes over the bimetal which regulates the warm to cold mix.....the engine, when warmed, breathes only filtered air at ambient or higher. Whilst there's no facility to COOL the incoming air on a hot day, I am led to believe theact of lifting above the earth will automatically do this
As the damper-pad can't be in two places at the same time, it's failsafe. The engine always gets an air supply.
Hope this shows that there ARE advances to be made to designs that appear to be frozen in the 1920's.
ISTR Porsche designing a modern-tech. engine , probably 30 years ago....just needed a single control......anyone else?