idle? overheats, running? cool as a cucumber

What is your question?

After being in bumper to bumper traffic my 2015 ford fiesta SE overheats and begins to affect my A/C. If the highway is clear and I am not in bumper to bumper traffic engine stays cool as a cucumber.

What makes this problem better or worse?

better is when the car is running and not idle

How long has your 2015 Ford Fiesta had this problem?

a few weeks