"Nuclear detonations cause three types of injuries: blast, thermal and radiation, as well as electromagnetic pulse (EMP) effects described further in a later section. (1) Blast injuries are caused by the overpressure wave traveling outwards from the center of the nuclear detonation. The types of injuries are the same as occur with conventional explosives and are further described in the next section. (2) Thermal injuries present as flash burns (burns from direct exposure to the thermal radiation pulse, typically ultraviolet, visible, and infrared waves) or flame burns (burns from materials set afire by the infrared energy wave igniting flammable materials). (3) Radiation injuries from a nuclear blast occur from two sources: prompt and residual. Prompt radiation effects occur due to the neutrons and high-energy gamma rays emitted immediately by the weapon. Severity depends on the weapon's yield, emission spectrum, and distance to the target. Residual radiation effects are due to emissions (typically alphas, betas, and low energy gammas) from fission fragments (the heavy atom products produced during fission) and activated environmental materials (when materials absorb radiation and become radioactive themselves). Collectively, these sources are called fallout. The amount of fallout depends on the weapon's yield, type, and height of burst, while the area affected depends heavily on the wind. The hazard to personnel depends on the level of radiation present and the duration of exposure". (JCS/DOD, CBRNE, Consequence Management (JP 3-41), 2006, p. I-8)