I had 40150 on A/C Mk2s from Preston to Blackpool N on 19/8/84, a very warm day. Passengers were wedging the sliding doors to the vestibules open with luggage, to get air flow from the droplights, and the guard was trying to shut them, moaning that the A/C wouldn't work with them open. He was roundly derided by the large number of "bashers" onboard.