I would second Bob's comments. Tai Chi is supposed to help with overall all health and vigor and so the sensations you describe should be one possible side effect of good practice.
I also think there is nothing in particular you need to do about this energy. In fact, paying too much attention to "side effects" can be detrimental to practice, since there can be many causes of such effects, and your development and experiences should change over time. For instance, feeling heat or a tingling sensation in your hands can mean that you are improving circulation to them and are just beginning to feel the increase; however, it might also mean that you are diverting excess circulation to them and are just beginning to feel the excess. In other words, enjoy the sensations, but do not chase them too much.
Some Taoist concepts that are part of the cultural heritage that underlies Tai Chi theory have very specific things to say about this type of energy, but I personally do not believe they have much relevance to modern Tai Chi practitioners.