DALLAS -- About 40 people attending a Tony Robbins seminar in downtown Dallas suffered minor burn injuries late Thursday after walking across hot coals in what is being described as a motivational event.

Trainers for Robbins' motivational seminars told WFAA walking on coals is a very emotional experience for people, and that participants were doing something they didn’t think was possible.

But that exercise was a painful reality for a large group of people at the “Unleash the Power Within” seminar.

Several ambulances were staged outside the Kay Bailey Hutchison Convention Center. Paramedics treated dozens of people from the sold-out program for burn injuries to their feet and legs.

Five people were taken to the hospital.

Conference volunteers said walking on hot coals has become a regular activity at Tony Robbins seminars across the world. Witnesses said some were distracted while walking across the coals.

"From my observation, there was someone in front of us and someone behind us on their cell phone, taking selfies and taking pictures,” said Jacqueline Luxemberg, who completed the fire walk. “[She asked others] to video record for her, so I think that that has a lot to do with it."

An estimated 7,000 people walked across the coals Thursday night.