Attack Environment Manual: Chapter 4, What the Planner Needs to Know about Electromagnetic Pluse [open pdf - 1MB]
"The discussion of EMP is aimed at the emergency planner and operator rather than the engineer or communications specialist. It is assumed that the reader is familiar with the material in the three preceding chapters. Since equipment damage from the electromagnetic (EMP) is most significant for a detonation outside the earth's atmosphere, other effects of high-altitude bursts (radio blackout and thermal radiation) have been included. Chapter 4 is the only chapter that discusses these high-altitude attack effects. One special point should be made about EMP effects. Exposure to the EMP fields is harmless to most people, the possible expectations being those dependent on electrical life support systems such as pacemakers. The energy collected on large metallic objects or long wire might conceivably be great enough to cause burns or electrocution of a person is touching the conductor or is close enough to become part of an arc path. Equipment effects, in contrast, can be severe. Commercial power is likely to be lost. Protected backup power sources and communication facilities are essential for any system which must operate immediately after attack. Unhardened electrical and electronic components may be damaged. This means that the emergency planner must identify capabilities need to perform the mission after and EMP event and initiate action to protect essential equipment."
Federal Emergency Management Agency 128; FEMA 128
United Stated Federal Emergency Management Agency, Learning Resource Center: http://www.lrc.fema.gov/