Flew rescue missions. Well, he had known that he had gone back for his friend and gotten in trouble for it, but it isn't quite the same thing to know that he had the training for it as well. He watches as John shines the light in his eyes and studies the other man's expression as he offers his advice, contemplating everything he's found out about the other man and everything he's still yet uncovering.

"I've got basic first aid training," Ianto replies. "You've obviously been trained for more than that."

He regards the other man for a moment longer before giving in to nod. "I'll let you know," he agrees, quietly. "I've had real concussions before. I know enough not to pretend to be fine when I'm not. I promise, alright?"