Per Segerbck ... keeps limited human company, because human technology makes him physically ill. How ill? On a walk last summer, he ran into one of his few neighbors, a man who lives in a cottage about 100 yards away. During their chat, the man's cellphone rang, and Segerbck, 54, was overcome by nausea. Within seconds, he was unconscious. Segerbck suffers from electro-hypersensitivity (EHS), which means he has severe physical reactions to the electromagnetic radiation produced by common consumer technologies, such as computers, televisions and cellphones. Symptoms range from burning or tingling sensations on the skin to dizziness, nausea, headaches, sleep disturbance and memory loss. In extreme cases like Segerbck's, breathing problems, heart palpitations and loss of consciousness can result. A cellphone has to be in use -- either making or receiving a call, or searching for a signal, when radiation levels are highest -- for it to have this kind of effect on Segerbck. Sweden is the only country in the world to recognize EHS as a functional impairment, and Segerbck's experience has been important in creating policy to address the condition. Swedish EHS sufferers -- about 3 percent of the population, or some 250,000 people, according to government statistics -- are entitled to similar rights and social services as those given to people who are blind or deaf. Today, local governments will pay to have the home of someone diagnosed with EHS electronically sanitized," if necessary, through the installation of metal shielding.