Due to federal restrictions contained in the current National Defense Authorization Act, citizens of the People's Republic of China-including the special administrative regions of Hong Kong and Macau-as well as citizens of the Islamic Republic of Iran, the Democratic People's Republic of Korea (North Korea), and the Russian Federation, who are not Lawful Permanent Residents ("green card" holders) are prohibited from accessing facilities that support the mission, functions, and operations of national security laboratories and nuclear weapons production facilities, which includes Los Alamos National Laboratory. Ability to sit, crawl, stand, walk, run, and climb; in addition to reaching overhead, horizontally, and down; Free from chronic wounds or chronic rashes which disrupt the integrity of the skin that would prevent safe entry into controlled areas; Ability to use stairways, fixed ladders, and ladders up to six feet.