So, what's really going on here? It all comes down to something called thermal conductivity. basically, this measures how well a material can conduct heat - and aluminum foil is actually pretty bad at it. It's like trying to get a cat to do tricks for treats - it's just not going to happen, no matter how hard you try!
But don't just take my word for it - there are actually some pretty crazy experiments you can do to test this out. For example, you can wrap a thermometer in aluminum foil and stick it in the oven - and guess what? The thermometer won't even budge! It's like the aluminum foil is somehow defying the laws of physics or something.
Why Doesn't Aluminum Foil Get Hot | The Tube
