What is the effect of electric shock on a person?

Electric shock has a negative effect on human organism. Your skin gets burn-like wounds and your nervous system can get severely damaged too.

That includes the part of the nervous system that controls your breathing, heartbeats, muscles etc... So in effect electric shock can cause ventricular fibrillation and stop your heart from beating.

If you are trying to save a person suffering from such injuries make sure you don't touch him while he is still in closed electrical circuit, you can break the circuit by shutting down the power, pushing or hitting the person with a heavy object might do the trick because he/she might let go of the object that is shocking him (but this doesn't mean that you get to throw a stone in his head). Your last solution should be running and jumping into him because you might close the circuit yourself and get seriously injured.