The various embodiments described herein include methods, devices, and systems for authenticating users. In one aspect, a method includes (1) determining an operating state of a heat source; (2) determining an occupancy of a dwelling that includes the heat source; (3) determining whether a heat-source alert condition is met; (4) in accordance with a determination that the heat-source alert condition is met, generating a heat-source alert; (5) receiving from a user acknowledgement of the heat-source alert, the acknowledgement including a first classification for the heat-source alert; and (6) determining that the acknowledgement includes the first classification for the heat-source alert; and (7) in accordance with the determination that the acknowledgement includes the first classification, modifying the heat-source alert condition for future heat-source alerts.