"Transmission line voltages vary from 44,000 to over 765,000 volts. The higher the voltage, the more electricity the line can carry."
I have been shocked with 120 V and it is very unpleasant. There is a surge of pain, and your arm becomes numb. Worst of all, you can't move your arm at all while the electricity is coursing through your body.
765,000 volts seems like it could do some damage to your body.