Final answer:
The appearance of smoke is not always an indication that heat is being produced.
Step-by-step explanation:
The statement is false. The appearance of smoke is not always an indication that heat is being produced. Smoke is commonly associated with the combustion of materials, which involves the release of heat. However, it is possible for smoke to be produced without the generation of heat. For example, smoking or vaping devices can produce smoke or vapor without any significant heat generation. Additionally, some chemical reactions can produce smoke without a substantial increase in temperature.
Therefore, while smoke often accompanies heat production, it is not a definitive indication of heat being generated.