¡Qué se escapa el gato! (literal translation – The cat is escaping)

Real meaning: It’s a funny way of asking someone to shut a door, usually to avoid the heat escaping in winter, or simply to get them to shut it after them.

Marina says: This sentence is very appropriate now that the cold days have finally arrived in Madrid. I remember the first time Ben heard this phrase from the man that looks after the garage where he parks his scooter. ¡Qué se escapa el gato!, said the man, and Ben was looking all over the place to see where the cat was It was only when he heard the same sentence a second time that he realised there isn’t a cat involved at all!

Ejemplos:
Pedro arrives at his country house on a very cold day and lights a fire in the sitting room. Meanwhile his friend José keeps going in and out of the room leaving the door wide open while he puts the food in the fridge and the suitcases away. Pedro says to José:
¡Que se escapa el gato!