SAN ANTONIO - With growing threats of natural disasters or incidents like mass shootings, knowing what to do before emergency responders arrive could mean life or death.

“You could bleed to death in as little as five minutes,” said Dr. Lillian Liao, the pediatric trauma medical director at University Hospital.

Medical professionals at University Hospital are taking active steps to prevent people from bleeding to death at scenes.

The certification training takes about an hour and shows people several ways to treat wounds.

“If you think of the 1980s and early 90s, when we’re teaching everyone how to do CPR, the Heimlich Maneuver – this is basically an extension of that,” said Liao.

Doctors say uncontrolled bleeding is the leading cause of death from trauma that can be prevented if treated.

“It could be from a motor vehicle crash. It could be when you’re injured doing outdoor events, and it could be in a mass shooting situation. In terms what’s going to be more common things are doing everyday events. You could be cooking in your own kitchen and cut yourself,” said Liao.

University Hospital is still providing training classes once a month. They are free and open to anyone. Anyone can register for a class at StopTheBleedTexas.org.