I have a bad head cold at the moment, and several people have knowingly said to me, “Ah, must be because of the change in seasons.” Seems unlikely to me. Any truth to it?
We do undergo “seasonal metabolic changes.”
As far as I’ve seen, there’s not a lot published on the effects of those changes on the functioning of the immune system.
There are a number of factors that could indirectly influance this. You turn of the AC, and the indoor humidity increases. You start using a heating system that has been collecting dust and mold all summer. Rodents move indoors. Your kids start school and hang out all day with a different bunch of kids. You go to a crowded movie theater for fun instead of the beach. The kids move from summer vacation routine to school routine which can be stressful for them and the parents that drive them about.
These are valid contributing factors, but none of them will give you a cold unless you’ve contracted a cold virus.