Common words:
* Thermometer: An instrument used to measure temperature.
* Thermodynamics: The study of how energy is transferred and transformed, especially as heat.
* Thermostat: A device that automatically regulates temperature.
* Thermos: A container designed to keep contents hot or cold.
* Thermal: Relating to heat.
* Thermite: A mixture of powdered aluminum and iron oxide that produces intense heat when ignited.
Less common words:
* Thermocouple: A device used to measure temperature by converting heat energy into electrical energy.
* Thermogenesis: The process of heat production in living organisms.
* Thermoelectricity: The generation of electricity by heating a junction between two different metals.
* Thermophilic: Preferring or thriving in high temperatures.
* Thermography: The process of creating images based on the infrared radiation emitted by objects.
* Thermoregulation: The process of maintaining a stable body temperature.
This is not an exhaustive list, but it gives you a good starting point for words beginning with "thermo-."