Ventilation

I used to remember that the Jubilee line was relatively tolerable during times of hot weather.

Recently, I have been on a number of trains where the 'blowers' behind the seats aren't blowing out anything at all, e.g. yesterday evening.

I wondered if the driver has any control over them - or do they operate automatically?

Also, I observed a new sign on the train about helping fellow passengers off at the next station if they feel unwell.