Electromagnetic Hypersensitivity, or EHS, is characterized by a "variety of non-specific symptoms, which afflicted individuals attribute to exposure to electromagnetic fields" (Wikipedia)
This is not a recognized medical disorder and several double-blind tests have indicated that EHS sufferers cannot determine the presence or lack of electromagnetic radiation. And yet one wonders if there is indeed some kind of correlation here, or if it is just a bunch of nervous nellies ascribing random symptoms to this condition (to put it crudely).
In the industrialized world, we do live among a continuous onslaught of all kinds of electromagnetic radiation, both natural and man-made; light, microwaves, radio, TV, WiFi, etc. While the levels of most of these are very low, how low is "low enough" for some people?