Yes , not only could it be a trap it happens , not a whole lot in the US , but I ' ve heard some incidences of that , but definitely abroad but there could also be an IDLH atmosphere in a factory where chemicals are used . Assess the situation should be emphasized even more in an industrial setting . In the line of work I am in , there are at least two types of gases that could potentially overcome someone , though the likelihood of this happening is very , very low . But still , we have and use these chemicals and the chemicals that could react with them to form the lethal gases stored properly , secondary containment , etc . If you see an otherwise healthy individual down in an industrial setting with no obvious cause and no witnesses , you have to check that there has not been a HCN or chlorine or other type of gas cloud in the air before rushing to do first aid . Luckily , our hazard communication program is so on point that the only first aid that has ever had to be done was the Heimlich maneuver on someone choking in the cafeteria .