NASA's Voyager Found a 30k-50k Kelvin "Wall" at the Edge of Solar System

It’s very odd to think of something extremely hot but with almost no density, and therefore very little heat transfer.

Closer to home you can get similar things when you grind metals for instance. The sparks are at extremely high temperatures, but won't typically start fires or cause burns (it depends) because they're just too small to impart much actual energy to anything they touch.

You only get fire risks when the things they touch are themselves tiny (like dust), so they're unable to absorb and spread the heat.

A similar thing happens when you bake with tinfoil. The foil will be at like 350 F, but you can still touch it basically immediately if you're willing to gamble that nothing with thermal mass is stuck to it where you can't see. It just doesn't have enough thermal mass on its own to burn you, but if there's a good-sized glob of cheese or water or something on the other side you can really be in for a nasty surprise.

I wonder if actual tin foil would behave differently from the aluminum foil that we are all now using.

https://en.wikipedia.org/wiki/Tin_foil

Tin foil and aluminum foil do have generally different properties. For instance, tin foil can disrupt mind control and aluminum foil can't, and corrosion effects are likely at least different. But any thin metal foil isn't going to be able to hold much heat, because there's just not that much material.