Can you catch bronchitis from not wearing a coat in the winter?

My friend has never worn a jacket this winter and she is now coughing and her spit is yellowish I think she has bronchitis but not 100% sure. I live in NY so it can get pretty cold. Do you think she has bronchitis? Also she always wears a hoodie with a short sleeve shirt underneath. And this is early in the morning say like 7:15am.