Final answer:
The protective coat worn by a firefighter for interior structural firefighting is called a bunker coat, a crucial piece of personal protective equipment.
Step-by-step explanation:
The protective coat worn by a firefighter for interior structural firefighting is known as a bunker coat. This term refers to the thick, fire-resistant jacket designed to protect firefighters from heat, flames, and other hazardous conditions. They are typically made of fire-resistant materials such as Nomex, which is also used in other protective gear for firefighting and racing car driving. Similar to the Nomex hoods worn by firefighters in Toronto or the full ensembles of Nomex gear worn by wildland firefighters and racing car drivers, bunker coats are an essential part of a firefighter's personal protective equipment, helping to mitigate the risks associated with firefighting activities.