Talk about a hot stunt! After traversing high wires above the Grand Canyon, Niagara Falls, and downtown Chicago, Wednesday night Nik Vallenda pulled off his most daring feat yet – crossing an active volcano! They call it the ‘Mouth of Hell’ – and you can see why. He had to wear a gas mask to protect against the toxic fumes emanating from below. His wife Erendira also braved the volcano, hanging over the lava lake by nothing but her teeth!