The FDA recommends that perishable food not be above 40℉ for more than 2 hours. This tiny little sensor can monitor the temperature in your lunch box and report over Bluetooth Low Energy (BLE).
The Bean's onboard LED is used to alert you if have passed the FDA's guidelines. When you open your lunchbox and see the flashing red light, you know it's time to find something else to eat.
The lunchbox monitor will also tell you the current temperature of your lunchbox and how long it's been above 40℉ (5℃). Don't expect to be able to read it when your lunch is in the fridge.