Abseiling grime-fighters drop in at Evelina London

Patients enjoyed watching the superhero window cleaners through the glass.

• Costumed window cleaners abseil to the rescue
• Young patients delight as giant windows are cleaned by superheroes

Meanwhile on a rooftop ... Batman, Spider-Man and Superman stare out across the city.

Then it happens: in a flash the three partners in crime-fighting leap forward and plunge downwards. High above the ground buckets, cloths and squeegies thrash around in a blur. And then, their job is done.

Watching from inside the building - a children's hospital - young fans smile and wave at the three super-friends safe in the knowledge that, once more, their windows are free of dirty marks and smears.

It might sound like some far-fetched comic book plot, but that's (more or less) exactly what happened last week when a team of window cleaners dropped in at Evelina London Children's Hospital to polish the building's massive windows.

The team, from All Clean Services, spice up their job of cleaning our hospital’s giant atrium by dressing up as superheroes and abseiling down the side of the building, to the delight of patients like 14-year-old Samir Hussein, a long-term patient.

"It was really exciting to see them just outside the window. Although he's a really good fighter, Batman doesn't really have any super-powers and I like Spider-Man, but Superman is the best so I gave him a wave," said Samir.

Four-month-old Kian Barham, who has been staying in hospital after having seizures, was perhaps too young to describe the experience, but according to mum Jodie, his delight was unmistakable.

"He's too young to know who they are, but he was really excited watching them in their colourful costumes. He was smiling all the way through and even gave a little wave to them," she said.

The team of superhero window cleaners were filmed by ITV London who featured them on their news programme. You can watch again on the ITV London Facebook page.