Is it harmful to let cold air conditioning blow on your face or body after sweating from exercising?

After exercise class, even after some stretching/cool down, I may still be sweating and when I get in the car to go home, the air blows right on my face and arms. It feels great, of course. Is it harmful in any way?

Not unless you have some sort of allergy and the a/c contains things you are allergic to; but then, it would affect you whether you were sweating or not. In this case, I have done what you are doing. I even come in and sit in a room with a ceiling fan after I mow the lawn (of course, the computer is there, too). The only time my husband and I have gotten ill from a/c was when it blew on us in someone else's car and we couldn't turn it away. Sometimes even fans at restaurants will have that affect - seem to start a cold just from the air blowing on us. I don't know the mechanism, but if your throats feels the least bit scratchy, turn the vents away from you. In all other cases, enjoy, enjoy, enjoy.

The only possible issue I can think of, is the cool air after heating your body/muscles up, may leave you a bit stiff when you get out of your car...your muscles will tend to cool down and maybe contract a bit. Other than that, it does feel good and I know of know actual adverse effects.

it can be dangerous, as if its not been used for a while it will be full of dust and things, but if its used often then its fine unless you put it to close and it could damage the air conditioner.

Hard to say. I think it might cause a cold because you are all wet, less elecrolights and with cold winds, you can get sick, even if it is above freezing point

no, but stupid people often like to say those kinds of things to control gullible people, it makes them feel important.