It burns no coal, no oil, no nuclear fuels and has no need for electricity.
It uses no man made explosions.
Yet it is far hotter than all ovens and fires and furnaces.
What is it?
Hint: It's something you hope to see most days.
Answer: The sun.
Although its energy is generated by the nuclear fusion of hydrogen nuclei into helium, no nuclear fuels (e.g. uranium) are involved.
You have the misfortune to own an unreliable clock. This one gains exactly 22 minutes every hour. It is now showing 10:15am and you know that is was correct at midnight, when you set it. The clock stopped three hours ago, what is the correct time now?