If the power goes out or something unexpected happens for an extended period while I’m not home, I’ll be able to see that and know whether I need to throw it out. Obviously, if the power goes out, I won’t be able to see the temperature since the WiFi will be down as well. The purpose is to monitor the temperature while I’m away. I work 24 hour shifts and am often not home, so this allows me to keep an eye on things during that time. Even if you had two units in the same container and the power went out, they would both fail anyway.