In the performance of an existing one must be always folks who help.1. equipment or structures that anchor the involved must have a smooth surface. No rough or sharp2. the device must not be located near the flame.
The performance must have helped a lot of people always 1. devices or structures that hold on to a flat surface. No sharp or jagged 2. Do not open flames.
In practice need an assistant in one person.1. Equipment or structures based on prescriptions must be smooth, no rough or sharp.2. Equipment must be close to the flames.