English: High voltage expert Henry Transtrom in 1913 lighting an incandescent light bulb attached to a Tesla coil by taking the other wire in his mouth. The coil produced an alternating voltage of 50 - 100 kV at a frequency of around 100 kHz to 1 MHz. This stunt works because the man's body functions as the plate of a capacitor to Earth. Each cycle, current flows back and forth through the wire and light bulb filament, charging and discharging the capacitance of the man's body. The light bulb is rated at 80 watts, so approximately that power is flowing through the man's body. This stunt is not painful because alternating currents above 10 kHz do not cause the sensation of electric shock; the text says that the only sensation is a feeling of warmth in the mouth if an insufficient length of wire used. During the early 20th century circus sideshow performers with names like Dr. Resisto, The Great Volta, and Madam Electra took hundreds of thousands of volts from Tesla coils though their body to perform spectacular stunts like this.

It used to be thought that, due to skin effect, high frequency currents traveled along the surface of the body and didn't penetrate to vital organs, so Tesla currents could cause skin burns but not shock and electrocution, but it is now known that these currents do penetrate into the body. Today exposing the body to Tesla currents like this is considered extremely dangerous and can result in electrocution. DON'T TRY THIS