I remember when this happened. It was a TSA E145. The next week, I was doing a quick turn in Denver and left the APU running because I wanted all hands on the baggage to expedite the turn. I hopped outside to let the ground know that I didn’t want external air and as a result of the infant incident, it was a new policy to automatically hook up external air and since I refused, I had to sign a form. After that, it was always quick and reliable getting external air for the rest of the summer, but the next summer all was forgotten and getting external air was like pulling teeth.