Irradiated persons as sources of radiation? The new HBO series "Chernobyl" is supposedly filled with misconceptions about radioactivity, among other things, according to an opinion piece published in "Forbes".
In particular: "The most egregious of “Chernobyl” sensationalism is the depiction of radiation as contagious, like a virus. The scientist-hero played by Emily Watson physically drags away the pregnant wife of a Chernobyl firefighter dying from Acute Radiation Syndrome (ARS)."
It has been argued that high doses of radiation would contaminate the actual living person receiving them. This was definitely something that was considered to be true at the Chernobyl disaster time, as a wife of one of the Chernobyl firefighters found out -- she was not permitted to hug her husband in the hospital, and she tells that she was told the hospital rooms became contaminated after hosting the firefighters.
Since there is a contradiction with what was said earlier, I presumed that it would be quite possible for the firefighters to have inhaled radioactive particles.
However, I was wondering, under what levels of exposure to radiation or additional factors -- without actually having radioactive material as leftovers in/on him -- could a person be irradiated to the point that his body became dangerously radioactive to people around him?
Would it be possible to be so contaminated and remain alive for appreciable amount of time?
 A: Dirt and isotopes that could be biologically consumed (like Iodine or Tritium) are surely a major contaminating factor in the industry and during the accidents. 
If we exclude it - 2 main ways to be activated are by neutron activation and photoactivation (high-energy gamma).
Neutron activation of a human in this context is possible if you are close to an unshielded working reactor, or nearby not later than 1 minute after it was stopped (so that late neutrons are still there). 


*

*Due to high relative biological effectiveness of neutron radiation - one can't take much neutron radiation without achieving lethal dose. You take lethal dose now, but activation products emit radiation over their half-life periods (which could be years). So human body can be made radioactive by neutron radiation, this radiation will be measurable, but it will hardly be lethal to people around you for a short period of time.

*Unfortunately you are not getting neutron radiation only. In such situation gamma radiation from decay products that were accumulated over months and years of fuel irradiation will be the dominant factor of accumulated dose that is not contributing to human body activation.

*Firefighter was near the reactor when nuclear fission has stopped, and there was almost no neutron radiation, only gamma/beta/alpha from decay products. So it was impossible to get any significant body activation this way. 


Photoactivation is not efficient for "low" energy gamma radiation one can see from decay products. Again, one will get lethal dose much faster than getting any significant activated radiation. Again, during activation you receive lethal dose now, while activation products will release radiation spread over the years. 
So answering your question directly - if we ignore dirt/biologically consumed isotopes, activation of human body to the level that is life-threatening for others in this type of nuclear accident is not feasible. It is a good idea to keep (pregnant or not) women away anyways though.
