HOUSTON -

Children at Texas Children's Hospital got a treat Friday morning when window washers suited up like superheroes and scaled the side of the building.

Hospital officials say they contract with a company to wash the hospital windows and figured asking them to suit up like superheroes would put a smile on the kids' faces.

Batman, Spiderman, Captain America and Superman all slowly made their way down the building, waving to kids through the windows.

It took nearly four hours to get down more than 20 floors.

Check out PHOTOS of the superheroes.