system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do we "catch" colds/flu/etc. in cold weather? Why are we more susceptible to getting sick in colder weather.

I was talking to a friend about this and we all know the situation, not supposed to go out in shorts, no shoes,  wet hair, blah blah in the cold. Why exactly does this make us susceptible to getting sick?
gpt
There is some evidence that cold makes your nose (nasal passage) a little more vulnerable to infection, but the primary reason is social.

When it's cold, we spend a lot of time indoors. This means we spend a lot more time in smaller spaces with more people. This just makes it easier for diseases to spread around to lots of people.