system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If heat is just atoms moving quickly, why does it hurt us?

For example: I put my hand in hot water (water with fast moving molecules) and I become burned and experience pain.

Why?
gpt
Because those fast moving molecules bump into your slow moving molecules, causing chaos at the molecular level, which is interpreted by your nerves as pain. If the skin is allowed to heat up enough, the molecules might get moving so fast that cells shake themselves apart, and your body has to send the immune system to clean up the mess (a blister)