After he's named lab safety officer, John Rennie must recover a precious sample from the bottom of a vat of liquid nitrogen. So he reaches in.

John Rennie is a science writer, editor, and lecturer based in New York. Viewers of The Weather Channel know him as the host of the original series Hacking The Planet and as one of the hosts of The Truth About… series of specials. He is also currently the editorial director of science for McGraw-Hill Professional, overseeing its highly respected AccessScience online reference and the McGraw-Hill Encyclopedia of Science & Technology.

This story originally aired on September 1, 2013.