Five stages of Minecraft burning:
1. Air temp gets too hot for mobs to survive
2. Water boils
3. All flammable blocks or things made by flammable blocks (like crafting tables) burn
4. Blocks will either melt, fuse together (iron liquid and copper-gold alloy), or turn into a gas
5. Everything will turn into a gas or plasma (if it hasn't already) and merge with the sun
And this is all Steve's fault for having really long arms.