Sentence:  A <WSD>hot zone</WSD> was established quickly. Unfortunately, these efforts were compromised by a few MPD officers on the scene who did not understand the serious nature of the potential chemical/biological threat and treated the incident more as a bomb scare. These officers initially crossed in and out of the <WSD>hot zone</WSD>, and could have contaminated themselves and other personnel had this been a real incident. 
Meaning of the word marked with <WSD> tags:  An area to which access is restricted because it is contaminated with radiation or a chemical or biological biohazard.