The head and legs of the condemned person are shaved and the prisoner is strapped into the chair. A moist sponge is placed on the head to aid conductivity. One electrode is attached to the head and a second attached to the leg to provide a closed circuit. At least two jolts of an electrical current are applied with the time and current depending on the physical state of the condemned person. Typically an initial voltage of around 2,000 volts is applied for up to 15 seconds to attempt both to induce unconsciousness and to stop the heart. The voltage is then lowered to reduce current flow to approximately 8 amps. The body of the person may heat up to approximately 138°F (59°C), and the electric current will generally cause severe damage to internal organs.
In theory, unconsciousness occurs in a fraction of a second. However, there are multiple reports of things going wrong during the process. There have been incidents of a person's head on fire; of burning transformers, and of a chair breaking down after the initial jolt and letting the condemned wait in pain on the floor of the execution room while the chair was fixed. In 1946, the electric chair failed to execute Willie Francis, who reportedly shrieked "Stop it! Let me breathe!" as he was being executed. It turned out that the portable electric chair had been improperly set up by an intoxicated trustee. A case was brought before the U.S. Supreme Court (Francis v. Resweber),[4] with lawyers for the condemned arguing that although Francis did not die, he had, in fact, been executed. The argument was rejected on the basis that re-execution did not violate the double jeopardy clause of the 5th Amendment of the US Constitution, and Francis was returned to the electric chair and successfully executed the following year.
Regardless of how the execution is performed, cleaning up afterwards is described as unpleasant. Skin is inevitably burned and prison workers have to separate the burnt skin from the electrodes. The initial flow of electric current may cause the person to lose control over many bodily functions, including muscle movement, urination and defecation. To mitigate this, alterations to modern electric chairs include padding and an inertia style retractable seat belt.