Yes, your body temperature can be lowered, somewhat. Your temperature actually varies over a pretty wide range all of the time, with daily cycles and in response with your activities and things like fighting infections. But your average temperature can trend higher or lower, corresponding to a higher or lower basal metabolism.

Other things that can happen when your metabolism slows down are that you get tired more often and more easily, your thought processes slow down, you sleep more. This happens to everyone as they age, and it can also happen from chronic stress, calorie restriction sufficient to trigger 'starvation mode', and anything else that causes your body to try to conserve energy for survival.