I agree opening the doors wouldn’t have made much of a differance. I live in southern Spain where temperatures reach 30c+ during peak times, and Seville is the warmest city in Spain, so opening the door would perhaps in fact make it worse.
I understand, after reading the other member’s posts, that indeed it is absolutely incorrect to deploy the slide. However, whatever the true story, I still do not feel sympathy for Ryanair in the slightest. This, in my opinion, adds to their poor reputation. Would this happen to Iberia, Vueling or other operators at Seville in that heat? Well, no because they pocket out to use the jet bridges which perhaps would allow passengers to disembark and wait in the cool terminal.
Either way, I still fly Ryanair (I’m flying at the weekend!), due to their cheap flights and comfortable routes….I’m not proud of it though!!! :p