Dr. Solar is a trained scientist, specializing in nuclear physics. Because he has been irradiated, he is now, in effect, a living nuclear battery. No longer dependent on food and water – in fact, no longer having either a heartbeat or a human metabolism – he obtains the energy he needs by exposing himself to nuclear radiation. After absorbing this radiation, especially in large amounts, his skin turns green. It is often several hours before his skin color returns to normal, especially if he has absorbed a larger amount of energy than normal. As a result, he has to wear clothing impregnated with cadmium and lead, and wear specially made dark glasses to protect his co-workers from radiation poisoning. The uniform he later adopts is also lined with cadmium and lead. A visor shields his eyes. On his belt there is almost always a small pouch containing radioisotopes, in pill or capsule form, which he can swallow to boost his energy level in an emergency.