So I am reading a book called "Voices from Chernobyl" where witnesses, nuclear plant workers, firefighters and other persons involved in the 1986 accident give testimony of their experiences.

The very first chapter goes along the lines of the wife of a firefighter that was dispatched for duty on the very day of the incident. He suffered acute radiation and was hospitalized. His wife remain with him throughout the last days before he died. One thing it was mentioned in the book very clearly is how nurses constantly tried to warn his wife not to touch him, hug him or even share objects with him.

In this article: https://www.livescience.com/13444-radiation-exposure-contagious.html, it is mentioned that a person who was exposed to radiation should not be a danger for others once his clothes have been disposed.

So, my question is, I am getting confused between the two readings. Is a person who has been exposed to a big dose of radiation a danger for other people? Why?