Scales that absorb heat
External heat is absorbed by the square scales on Fuecoco’s stomach and back, then converted into fire energy. These scales are always warm, and at times they can also grow very hot.
Overflowing Fire Energy
Flickering atop Fuecoco’s head is fire energy that is leaking out from inside the Pokémon’s body. When Fuecoco gets excited, its head spouts more flames.