All you need to know about EMF sensitivity...
http://www.wired.com/science/discoveries/news/2006/12/72265
I particularly like the refernce to Compulsive Risk Assessment Psychosis.
I seem to remember an article in New Scientist saying that in controlled conditions it was simply impossible for the supposedly afflicted to tell whether they were being subjected to such fields with any better than a 50/50 chance of success.
Give 'em an MRI and see what happens...