Call the RSPCA ! let them know how high the nest is. Keep the bird in a well ventilated box till RSPCA arrive but follow any interim advice they give you and don't keep checking to see if it's OK otherwise the bird will just be stressed and lose energy and dehydrate.

Good luck

Hi all,rather distressed woman brought small chick to me tonight. Went to where she found it and it is a house martin.intended to place back but had no ladders and unsure if they would reject it. Anyone know of anybody who would hand rear or any ideas.assuming it survives the night. Cheers