Children at Ann & Robert H. Lurie Children's Hospital of Chicago got a special surprise as three window washers dressed up as their favourite superheroes. 
The day has now been dubbed by hospital staff as "Superhero Day" and featured Captain America, Spider-Man and Batman scale the high walls of the hospital, to the delight of the young patients. 
Dr Stewart Goldman, a doctor at Lurie Children's Hosital, spoke of the importance of the day for the children saying: "There is power in laughter and joy and excitement."
Other children's hospitals around other states of the US such as Alabama and California have now joined in on the fun and also celebrate "Superhero Day". 
We can just imagine the sheer excitement on the little ones faces when Spider-Man appeared outside their window!