But I think it's a legitimate question of whether feeling the cold especially indoors is a sex-related or a gender-related difference, and I think someone could reasonably guess it was the former. Do women feel colder indoors than men because of e.g. clothing norms, or do females feel colder indoors than males regardless of their gender identity? I have read the explanation that the difference is mostly caused by the delta in metabolic rate -- in which case distinguishing by sex rather than gender seems clearer and more accurate.