In case there is a vacancy in the office of Vice President, the President shall nominate a Vice President who shall take office when they are confirmed by a majority vote of both Houses of Congress. If the President sends the Senate and House of Representatives a written statement that they are unable to continue being President, and until they send them a written note to the contrary, that office shall be transferred to the Vice President, and they shall act as Acting President. If the Vice President and a majority of either the Senate or House, or of such other body as Congress may by law provide, send to the Senate and the House of Representatives their written statement that the President is unable to discharge the powers and duties of that office, the Vice President shall immediately become Acting President. Then, when the President sends to the Senate and House of Representatives their written statement that no inability exists, he shall resume that office unless the Vice President and a majority of either the Senate or House, or of such other body as Congress may by law provide, send within four days to the Senate and the HOuse of Representatives a written statement that the President is continue in that office. Then Congress shall decide that issue, assembling within forty-eight hours for that purpose if not in session.
Resources Feel free to look at the original Bill of Rights.