The nurse hat is an item obtained from A Tail of Two Cats. During the quest, the hat is given to the player by the Apothecary in Varrock. It is used as part of a disguise to fool Unferth. Players can choose between a Doctor's hat or a Nurse's hat.
After the player has finished the quest, they can return to the apothecary and receive a new hat if their original has been lost.
On 9 June 2010, the cross on the Nurse hat was changed from red to green. This sparked some dislike from players on the forums. Mod Emilee stated that it was changed to avoid potential copyright issues. The original symbol is an emblem of the International Red Cross Movement. Other instances in the game, such as healer symbol in Barbarian Assault, were recoloured for the same reason.
In the forums, some players still have a red cross instead of the new green one on their hat.