She told London Live: “It was completely mad - we literally found out on Twitter. It was a surreal few weeks to be honest."
Inspiration for the film came from listening to an online recording of an emergency services call.
Bartleet said: “It was completely by chance – I was researching something else and I was looking online for what operators say when they answer a call.
“I just listened to a load of different calls and there was one – I just cannot even describe how frightening this call was.
“It was the fire service and I thought, ‘what that operator does is mad’. She is so calm and she is the only thing that that woman has in this terrifying, terrifying few moments of her life.
“They do not know if they are going to survive and so I just thought I would to see her point of view, as we do not see that very often.”
The 2016 BAFTA awards take place on Sunday 14 February.
