I’m not a doctor, but I think you could be on the right track with the thyroid thing. Graves disease runs in my mother’s side of the family. Before my mother was diagnosed, she was very thin (like MrHP), she was always hot (like MrHP), her eyes kind of bulged (like MrHP), and if memory serves, she did have a kind of strange metallic odor about her (also like MrHP). If he does have something like that, it’s just another piece of evidence that he’s really my long lost brother.