Chris Pratt and Chris Evans make surprise visit to children's hospital

Actors Chris Pratt and Chris Evans stunned patients at Seattle Children's Hospital in Washington on Saturday (07Mar15) by turning up for a surprise visit.

The stars posed for photographs with the youngsters, signed autographs and met with the patient's families.

Evans went dressed as his on-screen superhero Captain America in a bid to cheer the youngsters up.

Later that day he wrote on Twitter.com, "Amazing day at @seattlechildren (with Chris Pratt). Met some true super heroes! Feeling inspired, blessed, touched. Thank you w (with) all my heart."

A statement released by patient Oskar Beechum's mother Kelli reads, "Meeting them was a nice reprieve for us. So many of our visitors are doctors, and the conversations are medical. I can't wait to watch the Captain America movie with Oskar. It will be like he knows him personally now."

The visit comes a month after Pratt made good on his Super Bowl bet against Evans to dress up as his Guardians of the Galaxy character Star-Lord during a visit to a children's cancer facility in Boston, Massachusetts.