meet the parents who say it's a good thing to be young and aggressiv aggressive. >> aren't you worriedbout him getting hurt? >> and our world as you've never seen it before. a dragon fly in slow mo, a water droplet, even lightning. tonight, we'll show you the mysteries of the unseen world. >>> good evening. as a swirling 1,000-mile-long snowstorm is clobbering much of america, grounding flights, shutting down schools and generally making people miserable, we thought it might be useful to visit the coldest town in this country where they believe there's no such thing as bad weather, only bad year. sub zero is a way of life, and these people fully embrace it. abc's juju chang got a survival lesson. >> reporter: in the coldest city in the continental u.s., it's an average day. the wind chill, negative 38. >> a little chilly. >> but terry mason is not intimidated. >> here we go. >> reporter: in fact, the young mother of four is kbeti ingetti to do something most of us wouldn't ever dare, run about six miles in what's called the real winter games. the test of cold weather endurance in bruta