Every reading lands in one of four bands. One vocabulary, used everywhere — the light on the unit in the kitchen means the same thing as the chip on the dashboard and the word in the text message.
| Level | Heat index | What it means |
|---|---|---|
| Safe | below 80°F | Normal working conditions. |
| Caution | 80–89°F | Fatigue is possible with prolonged exposure. Worth watching. |
| Extreme Caution | 90–102°F | Heat cramps and heat exhaustion become likely. Time to act — water, rest, shade. |
| Danger | 103°F and above | Heat exhaustion likely, heat stroke possible. This is the level that escalates until a human responds. |
The device shows the band as a colour on its own screen, at the store, updated every couple of seconds — that display does not depend on the network, the dashboard, or anyone's phone. Remote oversight is what the dashboard adds on top.
A unit that cannot read its sensor shows an explicit sensor error rather than a colour. A heat monitor that displayed calm green while blind would be worse than one that showed nothing.