Before the demonstration, Giesbrecht, who is also a professor of thermal physiology at the University of Manitoba in Canada, explained that water pressure can greatly impact one’s chance of survival.

“When the water is even a foot or two above the bottom of the door, there’s like up to 500 pounds of pressure. That’s very difficult to push against,” Giesbrecht said.

To read the full article and to watch the full demonstration, please visit Good Morning America.