A simple coin, resting on a frozen cup of water, becomes your silent witness while you’re away. If everything stays rock solid, the coin remains on top and your food is safe. But if the ice softens during an outage, the coin sinks as it melts, freezing in place when the power returns. Its final position tells you what your eyes can’t: whether your food merely chilled or fully thawed and refroze.
When you come home, you’re not guessing—you’re deciding. Coin on top, you can relax. Stuck halfway, you inspect carefully and discard anything suspicious. Buried at the bottom, you know it’s time to throw perishable food away, no matter how “fine” it looks. This tiny, nearly free trick won’t stop outages, but it can protect your health, your family, and your peace of mind every time you lock the door and leave.