Me, too. I'm the weird chick, the one who keeps her house at 60 in the winter. It's increased muscle mass. The whole "fat insulates" is bullshit (except for those professional endurance swimmers, the ones who swim the English Channel and shit? They actually DO have the kind of fat that insulates, which is also a fuel source, really interesting stuff, they burn this insulating fat before they burn muscle).Heh I'm always warm like that though. I will be hot and sweat buckets in a 65F room while everyone else is putting on jackets/sweaters.
Anyway, I would think you should still feel some change in your metabolism, maybe not noticeable after a workout, but at least in the morning or evening. Granted, I'm 46, so I'm working from a lower natural baseline, the boost is more noticeable to me (I'm on peptides for repair/recovery/anti-aging currently until the rotator cuff heals).