Thermal Effect Protection
The thermal effect can result in both blindness and physical burns.
At 6 to 8 miles from the blast, the thermal pulse will cause third degree burns to anyone that is unshielded, and it would cause second degree burns at a distance of 8 to 10 miles. Even at 10 to 12 miles, where blast is no longer an issue, unprotected individuals would receive 1st degree burns.Thermal protection is extremely important, as burns would greatly complicate an otherwise survivable situation.
Never look directly at the fireball of a nuclear explosion. Because of the focusing action of the lens of the eye, especially at night when our pupils are open, thermal radiation can cause temporary and even permanent blindness. The thermal pulse travels at the speed of light and can last for a fraction of a second, up to several seconds. It also generally travels in straight lines.
Thermal protection is achieved by the ‘drop and cover’ method. If you do have warning, you should take cover behind a large structure, or go to a basement or culvert.