Seoul (CNN)It's a bitterly cold, bleak day on a military base in South Korea.
People are milling around calmly, clutching hot coffees, making small talk. Kids are chasing each other around an air hangar.
It's hard to believe they are practicing a high-stakes emergency evacuation that simulates what would happen if North Korea invaded.
"In real life, everyone would be wearing masks, rushing through places," says mom of two Nicholle Martinez. "There would be chaos everywhere. It would be scarier."