My theory is the dragons actually benefit immensely from sitting atop the gold piles as it acts as an amazing heat sink.

I don’t think that really fits with the metaphor but I wanted to say my piece regardless.

We don’t really have dwarven gold hoards anymore - I’m thinking we can prove climate change is caused by overheating dragons.

Everyone send me all your gold and I’ll prove it.

Why do you think places like Fort Knox have never been robbed? They have the best security guard.

People I wouldn't focus on heat sinking. I would focus on hoarding! Not letting others to share their precious things with them

I always thought dragons were reptilian and therefore cold blooded.

Yes, but being cold blooded doesn’t mean their blood is actually cold, it just means that they cannot internally regulate their temperature. For the majority of creatures that means they need external sources of warmth, dragons are unique in that they need external sources of “cool”.