12-year old Megan Gething and friend Mackenzie George were playing in a marsh in Massachusetts when Mackenzie tripped and cut her leg open.

Quick thinking Megan used a pair of shorts to be a make shift tourniquet on the wound and applied pressure to stop the bleeding.

"I knew it from a book I read," she said of the fiction trilogy. "I figured it was a well-known method of stopping bleeding," Megan told The Gloucester Times.

Mackenzie was taken to hospital and doctors said there was no permanent muscle or nerve damage. Her parents were grateful for Megan's quick thinking and help in what could have been a more serious situation had she lost more blood.

Mackenzie is expected to make a full recovery in the next month.

Source: The Gloucester Times.