Use the adjective uninvolved to describe someone who is emotionally distant or detached. If you are working with children, you may try to remain emotionally uninvolved, but kids have a way of worming into your heart when you least expect it.
Uninvolved also simply means "not involved," "not affected," or "not associated with." There are so many interesting after-school activities that you need not remain uninvolved; there really is something for every taste. You can join a sports team or marching band, art club or Future Farmers of America, or even math club or drama.