See also about electrical fires :
WARNING: C. Joule Effect, Inc. disclaims any liability: In this video some tests were made by professionals, and such tests should only be made by qualified professionals. The use of electricity under the conditions that have been filmed is very dangerous. Do not attempt to replicate these experiments if you are not a trained electrical professional and if you are not fully aware of what you are doing, the risks, and the proper ways to protect yourself and your surroundings. Glowing connections = joule effect heating, for example.