Heating or cooling of processes, equipment, or enclosed environments are within the purview of thermal engineering.
One or more of the following disciplines may be involved in solving a particular thermal engineering problem:
Thermal engineering may be practiced by mechanical engineers and chemical engineers.
One branch of knowledge used frequently in thermal engineering is that of thermofluids.
- Engineering : HVAC
- Cooling of computer chips 
- Boiler design
- Solar heating
- In design of combustion engines
- Thermal power plants
- ^ http://www.aavidthermalloy.com/technical/papers/engineering.shtml