Why does heat smell?

Heat by itself does not have a smell. What you may be referring to is the smell of something burning, which can occur when materials are exposed to high heat. The smell associated with burning is the result of chemical reactions that occur when the material breaks down and releases various gases and particles into the air.

For example, when you cook something on a stove, the high temperature causes the food to break down and release compounds like aldehydes, ketones, and other volatile organic compounds (VOCs). These VOCs are what give cooked food its characteristic aroma.

Similarly, when you burn wood or other fuels, the high heat causes the material to break down and release compounds like smoke, carbon monoxide, and other pollutants into the air. These gases and particles have distinct odors that are often associated with burning or smoke.

It's important to note that the smell of burning can be harmful, as some of the compounds released during combustion can irritate the respiratory system and pose a health risk. If you notice a strong odor of burning or smoke, it's important to ensure proper ventilation and assess the situation to prevent potential hazards.