Acute radiation poisoning happens when one is exposed to high amounts of ionizing radiation.
But there is a period of time where the person seems very healthy. This can last for hours or even days. Shortly after, they die immediately. Hence the term “walking ghost”
Why does this happen?
This is because what radiation poisoning does is it destroys the bone marrow. The bone marrow produces a lot of blood cells, so new blood cells can’t be made anymore.
However, the the blood cells that are already present in the body continues to circulate around and temporally work until they are “used up”
A similar effect happens in the intestinal tract.