They create a large surface area so that they can convect heat away from further away from the transistors meaning they are more effective at keeping it cool
The purpose of heat tape is to maintain and control pipes and vessels. This also keeps the heat that is being radiated from the pipes and vessels inside.
The purpose is to heat up a ingred
To produce heat.
The purpose of a heater is to heat up the room when it is cold; by using gas
The purpose of a thermostat on a running heat pump is to be able to determine the temperature the pump is operating at. This is used for regulating the heats needed.
The purpose is what it was without a HVAC system ... to make heat !
warn of heat wave
To cushion the table from the heat of a plate
Heat sinks are very important components in computers. The purpose of heat sinks in computers is to keep the computer from overheating. The heat sink removes heat from the processor, keeping the processor cool.
i think the purpose is to heat up water and/or other liquids.
The purpose of a cold heat soldering iron is to fuse electronic components, pipes and other metal materials together by melting solder as a connector which hardens as it cools. You can learn how a cold heat soldering iron works and it's different purpose at the HowStuffWorks website.
The heat sink absorbs the heat from the processor and then the fan disperses the heat.