| Clue | Source | Date |
|---|---|---|
| Element of a furnace, perhaps | ||
| Thermocouple in a gas furnace, e.g | The Washington Post Sunday | 17 Jun 2018 |
| Thermometer, e.g | New York Times | 10 Jan 2016 |
| Thermometer, e.g. | ||
| Home safety feature | LA Times Daily | 14 Nov 2015 |
| Home safety feature | ||
| Advanced missile feature |