Their used workout clothes.

Nat quickly darts back into the room and closes the door behind her.

"I have good news and bad news. Good news I have a full outfit. Bad news is that it's my gym clothes from this morning." She says in a sheepish voice while placing the clothes on top of the console they had been working at.

"Aww Nat really? Nothing else?" Mary shifts and turns to her fellow doctor.

"Yeah! Unless you have spare clothes for a human in your locker? No, didn't think so."