Given the colder temperatures, it is much more likely that the need for utilizing a hawk heater on a construction site is necessitated. As defined by NFPA 51B, this operation is classified as hot work and should be treated as such by the fire prevention program manager. In short, a BFD Hot Work permit should be sought in addition to a BFD General Permit, which allows for the storage of flammable gases on site. The General Permit must include any quantities that will not leave the site at the end of the day, including propane tanks for the hawk heaters. Like any hot work activity, any instances should be logged and a dedicated fire watch with a fire extinguisher should be present. In no case should propane be left unattended or stored inside a building, as regulated by the Boston Fire Prevention Code.