This weekend I was crewing at UPW (Unleash the Power Within) in London (UK).
I was part of the Fire Team that creates the Fire where the UPW participants walk over. And I can tell you, the fire is very very hot.

We've made sure that the participants walked safely over the hot coals while they where shouting "Cool Moss, cool moss". We frequently put fresh hot coals on the walkway.

Form my own firewalking experience I can tell you that if you find your center and put yourself in the right state you can walk those coals without buring yourself.

So, If you can walk over hot coals, what else can you do?