system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: since whales and dolphins breath air, why do they die so quickly when "beached"?
gpt
depending on what you mean by quick - they can live for at least a few hours outside the water (dolphins potentially a lot longer since weight is not such an issue), so that's not really what i would consider a quick death.

the factors are weight (they are lighter in water, heavier out of water, so they essentially crush themselves), temperature (water helps keep them cool, so outside water they overheat), and hydration (they drink a lot).

when you see people on a beach throwing water on them, its to help with the body temperature issue.