Electromagnetic feilds affect everyday life in many ways. The body has it's own electromagnetic feild that can be harnessed in various magical ways. Understanding electromagnetism is nessecary for understanding certain magical processes and how control internal and external energy. Here are some helpful resources to do with this subject:
The Human Electromagnetic Feild by Humanfrequencies.com part 1, 2, and 3. They are well researched and site their sources but the website is based in Reiki, a practice i do not work with and haven't heard great things about. Take what they say with a grain of salt and look into the sources. (the link is for 1, 2 and 3 are linked at the end of the article.)