My daughter is in the upstairs back room (small room) which has the outside wall.
She says that the wall is very very cold of a night lately and one of the pillows she had down the side of the bed against the wall was actually wet with water moisture.
I said to the wife I'd ask what it means / what to be done.
In my limited knowledge I said I think the wall needs re-pointing.
It is a 1930's house, so single brick wall I'm sure.