Hot Feet

Trouble at the motivational event:

Ms. Kaderi was one of nearly two dozen who were injured on Thursday, the first night of Mr. Robbins’s “Unleash the Power Within” seminar, which included a fire walk as a signature experience. She said she did not seek medical attention, but many of those hurt reported second- or third-degree burns, Capt. Reggie Williams of the San Jose Fire Department told The Associated Press.

And yet, most were OK:

About 6,000 people reportedly participated in the firewalk. Why were most of them not injured?

Because coal isn’t a very good conductor of heat. In other words, though coal can get very hot—usually between 1,000 F and 2,000 F—it can’t transmit the heat to other materials very efficiently. When flesh comes into contact with a heated material that’s a good conductor of heat, such as metal, it usually results in a burn because the metal heats up the flesh quickly. But coal—and especially the ash coating a burning coal—doesn’t conduct heat very well.

...That said, there are dangers associated with firewalking: If you stand on a hot coal for too long instead of moving quickly or if there are any bits of metal, wood, or sap (which are better thermal conductors than coal) in the fire, you could get burned. ... The scope of Robbins’ firewalk in San Jose—6,000 people sharing a dozen 10-foot-long lanes of coals—might have made it more likely for firewalkers to get held up on the coals, increasing their chance of being injured. (Most traditional firewalking rituals involve only one dozen to two dozen people on a single lane of coals.)

...Many firewalking proponents claim that successful firewalking is the result of either a heightened psychological state or supernatural protection. ... But physicists and anthropologists who have participated in firewalks deny that any particular state of mind is required for successful firewalking, so long as the coals are properly prepared and you don’t stay in the fire too long.