To warn of hazardous conditions in a monitored space, the presence of an object bearing an RFID tag is detected using an RFID tag reader. Objects may be, for example, human beings, vehicles, or stationary materiel. A determination is made as to whether the object poses a hazard by, for example, reading data from the RFID tag or by accessing a database using data read from the RFID tag. If the object is determined to pose a hazard, the nature of the hazard is determined from the RFID tag or the database, and warning about the nature of the hazard is provided proximate to the monitored space. In some embodiments, providing the warning may be conditional upon detecting the concurrent presence of two objects in the monitored space.