Structural fire is occurring in residential or industrial buildings, which means indoors.
This is quite dangerous because all the smoke and toxic gases building up in these closed buildings. Temperature can rise up to extremely high values, especially if fire catches in industrial buildings where fuel or petrol is being used. Fire can also destroy carrying walls causing the building to collapse.
Some of the gases produced during fire are carbon monoxide and carbon dioxide which, found in high enough concentration, cause oxygen deficiency.
One may know how close the molecules within the substances are packed together. Hot substances have molecules that are farther apart, cold substances have molecules that are more compact/closer together.
