Learned my lesson after a trip last week… I have sensors for nearly everything, but somehow totally forgot about the Fridge / Freezer.
A power outage made my fridge lose it’s mind and turn off cooling, even after it powered back up. Unplug / replug seems to have fixed it, but all the food was spoiled when we got home. Simple $10 temperature sensor could have saved everything!
I bought a battery-powered (2xAAA) zigbee temperature/humidity sensor about 6 months ago and haven’t replaced its batteries yet.