Why is it you can stick your arm in an oven at 350° F for a short time and feel no ill effects, but if you touched the metal walls of the oven you'd be instantly burned?

Question

Why is it you can stick your arm in an oven at 350° F for a short time and feel no ill effects, but if you touched the metal walls of the oven you'd be instantly burned?

Group of answer choices

The air inside the oven actually has no temperature

Air is a poor conductor of heat

Air has a higher heat capacity than metal

The metal is actually much hotter than 350° F

 

Answer 1

So, burning basically involves rapid heat transfer. In this case, the heat is either going from the metal pan to your hand or from the hot air to your hand. The 2nd law of Thermodynamics tells us that the oven, the air inside, and the pan should all be about the same temperature, depending on how long they've been next to each other.

Different materials have different values of "thermal conductivity" -- how fast they allow heat to move through them (and, in this case, into your hand). You can look these up online and compare the values for some metals to the value for air.