Heat Shadows
Burn patterns can be used to pinpoint fire origin by observing where the shadowing of heat has occurred. “Shadows” of relatively undamaged material may be visible in the area surrounding the heat source if those materials were blocked from the heat. An electrical conductor overheated by internal resistance will exhibit damage along its entire length from the power source to ground. Alternatively, an electrical conductor damaged by a fire may have insulation remaining in areas protected from the heat.