Nuclear weapon effects

Thermal Radiation

The intense pulse of light and infrared radiation emitted by the fireball of a nuclear detonation, capable of causing burns and igniting fires at long distances.

Thermal radiation accounts for roughly 35% of the energy released by a nuclear weapon. It travels at the speed of light and arrives before the blast wave. Third-degree burns can occur out to several kilometers for strategic-yield weapons. Thermal-radiation radius scales with yield to the 0.41 power, faster than blast.

Related terms

See the full Nuclear Weapons Glossary.