If fire works in Game of Thrones as it does in the real world, then the fire that Viserion is spitting is actually hotter than regular fire. As a flame grows hotter, its color changes from red, to ...

Also, blue fire is hotter than red or yellow flames. But King's Landing is made of STONE. ... That's way hotter than your average oven (375 degrees Fahrenheit for fresh-baked direwolf bread).