It may seem silly to ask and/or obvious to answer.
I can't recall exact episode titles I'm afraid, but when Deanna was pregnant, Data was assumed by Pulaski to be cold to the touch.
In contrast, the child in Pen Pal had no lines indicating this fact, and she of all witnesses would be likely to say he was cold, even if she had known prior to their meeting.
This might be inaccurate to the trek-lore of the androids but since there is mechanical functions working about him, perhaps, under my own personal theory, rather than typical human warmth upon his bioplasmic skin, he might have artificial warmth, like that of a surge protector of computer cords. Or maybe I am terribly wrong and there is none; rendering him cold like the surface of washing machines.
What causes this roller-coaster of debate is that during Ensigns of Command, his new friend, a woman, kissed him and later on, out of support, and she clearly enjoyed it. I think he has to have warmth. I can't imagine anyone having her expression kissing cold lips.
Anyway, I'd like some input on this. It's boggling my mind.