What makes me feel a cold sensation passing through my solar plexus and heart chakras?

When I meditate, I always experience a cold wave moving in between my solar plexus and heart chakras. It is not painful but is constant and distracting. It is like energy is passing through, yet in a manner that I do not understand. Is it a healing sign, blockage, or something else? Why should I experience the cold feeling in between these two chakras?